/* $Id$ */

#include <stdio.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "gd_intern.h"

/* 2.03: don't include zlib here or we can't build without PNG */
#include "gd.h"
#include "gdhelpers.h"
#include "gd_color.h"
#include "gd_errors.h"

/* 2.0.12: this now checks the clipping rectangle */
#define gdImageBoundsSafeMacro(im, x, y) (!((((y) < (im)->cy1) || ((y) > (im)->cy2)) || (((x) < (im)->cx1) || ((x) > (im)->cx2))))

#ifdef _OSD_POSIX		/* BS2000 uses the EBCDIC char set instead of ASCII */
#define CHARSET_EBCDIC
#define __attribute__(any)	/*nothing */
#endif
/*_OSD_POSIX*/

#ifndef CHARSET_EBCDIC
#define ASC(ch)  ch
#else /*CHARSET_EBCDIC */
#define ASC(ch) gd_toascii[(unsigned char)ch]
static const unsigned char gd_toascii[256] = {
	/*00 */ 0x00, 0x01, 0x02, 0x03, 0x85, 0x09, 0x86, 0x7f,
	0x87, 0x8d, 0x8e, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,	/*................ */
	/*10 */ 0x10, 0x11, 0x12, 0x13, 0x8f, 0x0a, 0x08, 0x97,
	0x18, 0x19, 0x9c, 0x9d, 0x1c, 0x1d, 0x1e, 0x1f,	/*................ */
	/*20 */ 0x80, 0x81, 0x82, 0x83, 0x84, 0x92, 0x17, 0x1b,
	0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x05, 0x06, 0x07,	/*................ */
	/*30 */ 0x90, 0x91, 0x16, 0x93, 0x94, 0x95, 0x96, 0x04,
	0x98, 0x99, 0x9a, 0x9b, 0x14, 0x15, 0x9e, 0x1a,	/*................ */
	/*40 */ 0x20, 0xa0, 0xe2, 0xe4, 0xe0, 0xe1, 0xe3, 0xe5,
	0xe7, 0xf1, 0x60, 0x2e, 0x3c, 0x28, 0x2b, 0x7c,	/* .........`.<(+| */
	/*50 */ 0x26, 0xe9, 0xea, 0xeb, 0xe8, 0xed, 0xee, 0xef,
	0xec, 0xdf, 0x21, 0x24, 0x2a, 0x29, 0x3b, 0x9f,	/*&.........!$*);. */
	/*60 */ 0x2d, 0x2f, 0xc2, 0xc4, 0xc0, 0xc1, 0xc3, 0xc5,
	0xc7, 0xd1, 0x5e, 0x2c, 0x25, 0x5f, 0x3e, 0x3f,
	/*-/........^,%_>?*/
	/*70 */ 0xf8, 0xc9, 0xca, 0xcb, 0xc8, 0xcd, 0xce, 0xcf,
	0xcc, 0xa8, 0x3a, 0x23, 0x40, 0x27, 0x3d, 0x22,	/*..........:#@'=" */
	/*80 */ 0xd8, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
	0x68, 0x69, 0xab, 0xbb, 0xf0, 0xfd, 0xfe, 0xb1,	/*.abcdefghi...... */
	/*90 */ 0xb0, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70,
	0x71, 0x72, 0xaa, 0xba, 0xe6, 0xb8, 0xc6, 0xa4,	/*.jklmnopqr...... */
	/*a0 */ 0xb5, 0xaf, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
	0x79, 0x7a, 0xa1, 0xbf, 0xd0, 0xdd, 0xde, 0xae,	/*..stuvwxyz...... */
	/*b0 */ 0xa2, 0xa3, 0xa5, 0xb7, 0xa9, 0xa7, 0xb6, 0xbc,
	0xbd, 0xbe, 0xac, 0x5b, 0x5c, 0x5d, 0xb4, 0xd7,	/*...........[\].. */
	/*c0 */ 0xf9, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
	0x48, 0x49, 0xad, 0xf4, 0xf6, 0xf2, 0xf3, 0xf5,	/*.ABCDEFGHI...... */
	/*d0 */ 0xa6, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50,
	0x51, 0x52, 0xb9, 0xfb, 0xfc, 0xdb, 0xfa, 0xff,	/*.JKLMNOPQR...... */
	/*e0 */ 0xd9, 0xf7, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
	0x59, 0x5a, 0xb2, 0xd4, 0xd6, 0xd2, 0xd3, 0xd5,	/*..STUVWXYZ...... */
	/*f0 */ 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
	0x38, 0x39, 0xb3, 0x7b, 0xdc, 0x7d, 0xda, 0x7e	/*0123456789.{.}.~ */
};
#endif /*CHARSET_EBCDIC */

extern const int gdCosT[];
extern const int gdSinT[];

void gd_stderr_error(int priority, const char *format, va_list args)
{
	switch (priority) {
	case GD_ERROR:
		fputs("GD Error: ", stderr);
		break;
	case GD_WARNING:
		fputs("GD Warning: ", stderr);
		break;
	case GD_NOTICE:
		fputs("GD Notice: ", stderr);
		break;
	case GD_INFO:
		fputs("GD Info: ", stderr);
		break;
	case GD_DEBUG:
		fputs("GD Debug: ", stderr);
		break;
	}
	vfprintf(stderr, format, args);
	fflush(stderr);
}

static gdErrorMethod gd_error_method = gd_stderr_error;

void gd_error(const char *format, ...)
{
	va_list args;

	va_start(args, format);
	gd_error_ex(GD_WARNING, format, args);
	va_end(args);
}
void gd_error_ex(int priority, const char *format, ...)
{
	va_list args;

	va_start(args, format);
	if (gd_error_method) {
		gd_error_method(priority, format, args);
	}
	va_end(args);
}

BGD_DECLARE(void) gdSetErrorMethod(gdErrorMethod error_method)
{
	gd_error_method = error_method;
}

BGD_DECLARE(void) gdClearErrorMethod(void)
{
	gd_error_method = gd_stderr_error;
}

static void gdImageBrushApply (gdImagePtr im, int x, int y);
static void gdImageTileApply (gdImagePtr im, int x, int y);
BGD_DECLARE(int) gdImageGetTrueColorPixel (gdImagePtr im, int x, int y);

BGD_DECLARE(gdImagePtr) gdImageCreate (int sx, int sy)
{
	int i;
	gdImagePtr im;

	if (overflow2(sizeof (unsigned char *), sy)) {
		return NULL;
	}
	if (overflow2(sizeof (unsigned char *), sx)) {
		return NULL;
	}

	im = (gdImage *) gdCalloc(1, sizeof(gdImage));
	if (!im) {
		return NULL;
	}

	/* Row-major ever since gd 1.3 */
	im->pixels = (unsigned char **) gdMalloc (sizeof (unsigned char *) * sy);
	if (!im->pixels) {
		gdFree(im);
		return NULL;
	}

	im->polyInts = 0;
	im->polyAllocated = 0;
	im->brush = 0;
	im->tile = 0;
	im->style = 0;
	for (i = 0; (i < sy); i++) {
		/* Row-major ever since gd 1.3 */
		im->pixels[i] = (unsigned char *) gdCalloc (sx, sizeof (unsigned char));
		if (!im->pixels[i]) {
			for (--i ; i >= 0; i--) {
				gdFree(im->pixels[i]);
			}
			gdFree(im->pixels);
			gdFree(im);
			return NULL;
		}

	}
	im->sx = sx;
	im->sy = sy;
	im->colorsTotal = 0;
	im->transparent = (-1);
	im->interlace = 0;
	im->thick = 1;
	im->AA = 0;
	for (i = 0; (i < gdMaxColors); i++) {
		im->open[i] = 1;
	};
	im->trueColor = 0;
	im->tpixels = 0;
	im->cx1 = 0;
	im->cy1 = 0;
	im->cx2 = im->sx - 1;
	im->cy2 = im->sy - 1;
	im->res_x = GD_RESOLUTION;
	im->res_y = GD_RESOLUTION;
	im->interpolation = NULL;
	im->interpolation_id = GD_BILINEAR_FIXED;
	return im;
}

BGD_DECLARE(gdImagePtr) gdImageCreateTrueColor (int sx, int sy)
{
	int i;
	gdImagePtr im;

	if (overflow2(sx, sy)) {
		return NULL;
	}

	if (overflow2(sizeof (int *), sy)) {
		return 0;
	}

	if (overflow2(sizeof(int), sx)) {
		return NULL;
	}

	im = (gdImage *) gdMalloc (sizeof (gdImage));
	if (!im) {
		return 0;
	}
	memset (im, 0, sizeof (gdImage));

	im->tpixels = (int **) gdMalloc (sizeof (int *) * sy);
	if (!im->tpixels) {
		gdFree(im);
		return 0;
	}
	im->polyInts = 0;
	im->polyAllocated = 0;
	im->brush = 0;
	im->tile = 0;
	im->style = 0;
	for (i = 0; (i < sy); i++) {
		im->tpixels[i] = (int *) gdCalloc (sx, sizeof (int));
		if (!im->tpixels[i]) {
			/* 2.0.34 */
			i--;
			while (i >= 0) {
				gdFree(im->tpixels[i]);
				i--;
			}
			gdFree(im->tpixels);
			gdFree(im);
			return 0;
		}
	}
	im->sx = sx;
	im->sy = sy;
	im->transparent = (-1);
	im->interlace = 0;
	im->trueColor = 1;
	/* 2.0.2: alpha blending is now on by default, and saving of alpha is
	   off by default. This allows font antialiasing to work as expected
	   on the first try in JPEGs -- quite important -- and also allows
	   for smaller PNGs when saving of alpha channel is not really
	   desired, which it usually isn't! */
	im->saveAlphaFlag = 0;
	im->alphaBlendingFlag = 1;
	im->thick = 1;
	im->AA = 0;
	im->cx1 = 0;
	im->cy1 = 0;
	im->cx2 = im->sx - 1;
	im->cy2 = im->sy - 1;
	im->res_x = GD_RESOLUTION;
	im->res_y = GD_RESOLUTION;
	im->interpolation = NULL;
	im->interpolation_id = GD_BILINEAR_FIXED;
	return im;
}

BGD_DECLARE(void) gdImageDestroy (gdImagePtr im)
{
	int i;
	if (im->pixels) {
		for (i = 0; (i < im->sy); i++) {
			gdFree (im->pixels[i]);
		}
		gdFree (im->pixels);
	}
	if (im->tpixels) {
		for (i = 0; (i < im->sy); i++) {
			gdFree (im->tpixels[i]);
		}
		gdFree (im->tpixels);
	}
	if (im->polyInts) {
		gdFree (im->polyInts);
	}
	if (im->style) {
		gdFree (im->style);
	}
	gdFree (im);
}

BGD_DECLARE(int) gdImageColorClosest (gdImagePtr im, int r, int g, int b)
{
	return gdImageColorClosestAlpha (im, r, g, b, gdAlphaOpaque);
}

BGD_DECLARE(int) gdImageColorClosestAlpha (gdImagePtr im, int r, int g, int b, int a)
{
	int i;
	long rd, gd, bd, ad;
	int ct = (-1);
	int first = 1;
	long mindist = 0;
	if (im->trueColor) {
		return gdTrueColorAlpha (r, g, b, a);
	}
	for (i = 0; (i < (im->colorsTotal)); i++) {
		long dist;
		if (im->open[i]) {
			continue;
		}
		rd = (im->red[i] - r);
		gd = (im->green[i] - g);
		bd = (im->blue[i] - b);
		/* gd 2.02: whoops, was - b (thanks to David Marwood) */
		/* gd 2.16: was blue rather than alpha! Geez! Thanks to
		   Artur Jakub Jerzak */
		ad = (im->alpha[i] - a);
		dist = rd * rd + gd * gd + bd * bd + ad * ad;
		if (first || (dist < mindist)) {
			mindist = dist;
			ct = i;
			first = 0;
		}
	}
	return ct;
}

/* This code is taken from http://www.acm.org/jgt/papers/SmithLyons96/hwb_rgb.html, an article
 * on colour conversion to/from RBG and HWB colour systems.
 * It has been modified to return the converted value as a * parameter.
 */

#define RETURN_HWB(h, w, b) {HWB->H = h; HWB->W = w; HWB->B = b; return HWB;}
#define RETURN_RGB(r, g, b) {RGB->R = r; RGB->G = g; RGB->B = b; return RGB;}
#define HWB_UNDEFINED -1
#define SETUP_RGB(s, r, g, b) {s.R = r/255.0; s.G = g/255.0; s.B = b/255.0;}

#define MIN(a,b) ((a)<(b)?(a):(b))
#define MIN3(a,b,c) ((a)<(b)?(MIN(a,c)):(MIN(b,c)))
#define MAX(a,b) ((a)<(b)?(b):(a))
#define MAX3(a,b,c) ((a)<(b)?(MAX(b,c)):(MAX(a,c)))


/*
 * Theoretically, hue 0 (pure red) is identical to hue 6 in these transforms. Pure
 * red always maps to 6 in this implementation. Therefore UNDEFINED can be
 * defined as 0 in situations where only unsigned numbers are desired.
 */
typedef struct {
	float R, G, B;
}
RGBType;
typedef struct {
	float H, W, B;
}
HWBType;

static HWBType *
RGB_to_HWB (RGBType RGB, HWBType * HWB)
{

	/*
	 * RGB are each on [0, 1]. W and B are returned on [0, 1] and H is
	 * returned on [0, 6]. Exception: H is returned UNDEFINED if W == 1 - B.
	 */

	float R = RGB.R, G = RGB.G, B = RGB.B, w, v, b, f;
	int i;

	w = MIN3 (R, G, B);
	v = MAX3 (R, G, B);
	b = 1 - v;
	if (v == w)
		RETURN_HWB (HWB_UNDEFINED, w, b);
	f = (R == w) ? G - B : ((G == w) ? B - R : R - G);
	i = (R == w) ? 3 : ((G == w) ? 5 : 1);
	RETURN_HWB (i - f / (v - w), w, b);

}

static float
HWB_Diff (int r1, int g1, int b1, int r2, int g2, int b2)
{
	RGBType RGB1, RGB2;
	HWBType HWB1, HWB2;
	float diff;

	SETUP_RGB (RGB1, r1, g1, b1);
	SETUP_RGB (RGB2, r2, g2, b2);

	RGB_to_HWB (RGB1, &HWB1);
	RGB_to_HWB (RGB2, &HWB2);

	/*
	 * I made this bit up; it seems to produce OK results, and it is certainly
	 * more visually correct than the current RGB metric. (PJW)
	 */

	if ((HWB1.H == HWB_UNDEFINED) || (HWB2.H == HWB_UNDEFINED)) {
		diff = 0;			/* Undefined hues always match... */
	} else {
		diff = fabs (HWB1.H - HWB2.H);
		if (diff > 3) {
			diff = 6 - diff;	/* Remember, it's a colour circle */
		}
	}

	diff =
	    diff * diff + (HWB1.W - HWB2.W) * (HWB1.W - HWB2.W) + (HWB1.B -
	            HWB2.B) * (HWB1.B -
	                       HWB2.B);

	return diff;
}


#if 0
/*
 * This is not actually used, but is here for completeness, in case someone wants to
 * use the HWB stuff for anything else...
 */
static RGBType *
HWB_to_RGB (HWBType HWB, RGBType * RGB)
{

	/*
	 * H is given on [0, 6] or UNDEFINED. W and B are given on [0, 1].
	 * RGB are each returned on [0, 1].
	 */

	float h = HWB.H, w = HWB.W, b = HWB.B, v, n, f;
	int i;

	v = 1 - b;
	if (h == HWB_UNDEFINED)
		RETURN_RGB (v, v, v);
	i = floor (h);
	f = h - i;
	if (i & 1)
		f = 1 - f;			/* if i is odd */
	n = w + f * (v - w);		/* linear interpolation between w and v */
	switch (i) {
	case 6:
	case 0:
		RETURN_RGB (v, n, w);
	case 1:
		RETURN_RGB (n, v, w);
	case 2:
		RETURN_RGB (w, v, n);
	case 3:
		RETURN_RGB (w, n, v);
	case 4:
		RETURN_RGB (n, w, v);
	case 5:
		RETURN_RGB (v, w, n);
	}

	return RGB;

}
#endif

BGD_DECLARE(int) gdImageColorClosestHWB (gdImagePtr im, int r, int g, int b)
{
	int i;
	/* long rd, gd, bd; */
	int ct = (-1);
	int first = 1;
	float mindist = 0;
	if (im->trueColor) {
		return gdTrueColor (r, g, b);
	}
	for (i = 0; (i < (im->colorsTotal)); i++) {
		float dist;
		if (im->open[i]) {
			continue;
		}
		dist = HWB_Diff (im->red[i], im->green[i], im->blue[i], r, g, b);
		if (first || (dist < mindist)) {
			mindist = dist;
			ct = i;
			first = 0;
		}
	}
	return ct;
}

BGD_DECLARE(int) gdImageColorExact (gdImagePtr im, int r, int g, int b)
{
	return gdImageColorExactAlpha (im, r, g, b, gdAlphaOpaque);
}

BGD_DECLARE(int) gdImageColorExactAlpha (gdImagePtr im, int r, int g, int b, int a)
{
	int i;
	if (im->trueColor) {
		return gdTrueColorAlpha (r, g, b, a);
	}
	for (i = 0; (i < (im->colorsTotal)); i++) {
		if (im->open[i]) {
			continue;
		}
		if ((im->red[i] == r) &&
		        (im->green[i] == g) && (im->blue[i] == b) && (im->alpha[i] == a)) {
			return i;
		}
	}
	return -1;
}

BGD_DECLARE(int) gdImageColorAllocate (gdImagePtr im, int r, int g, int b)
{
	return gdImageColorAllocateAlpha (im, r, g, b, gdAlphaOpaque);
}

BGD_DECLARE(int) gdImageColorAllocateAlpha (gdImagePtr im, int r, int g, int b, int a)
{
	int i;
	int ct = (-1);
	if (im->trueColor) {
		return gdTrueColorAlpha (r, g, b, a);
	}
	for (i = 0; (i < (im->colorsTotal)); i++) {
		if (im->open[i]) {
			ct = i;
			break;
		}
	}
	if (ct == (-1)) {
		ct = im->colorsTotal;
		if (ct == gdMaxColors) {
			return -1;
		}
		im->colorsTotal++;
	}
	im->red[ct] = r;
	im->green[ct] = g;
	im->blue[ct] = b;
	im->alpha[ct] = a;
	im->open[ct] = 0;
	return ct;
}

/*
 * gdImageColorResolve is an alternative for the code fragment:
 *
 *      if ((color=gdImageColorExact(im,R,G,B)) < 0)
 *        if ((color=gdImageColorAllocate(im,R,G,B)) < 0)
 *          color=gdImageColorClosest(im,R,G,B);
 *
 * in a single function.    Its advantage is that it is guaranteed to
 * return a color index in one search over the color table.
 */

BGD_DECLARE(int) gdImageColorResolve (gdImagePtr im, int r, int g, int b)
{
	return gdImageColorResolveAlpha (im, r, g, b, gdAlphaOpaque);
}

BGD_DECLARE(int) gdImageColorResolveAlpha (gdImagePtr im, int r, int g, int b, int a)
{
	int c;
	int ct = -1;
	int op = -1;
	long rd, gd, bd, ad, dist;
	long mindist = 4 * 255 * 255;	/* init to max poss dist */
	if (im->trueColor) {
		return gdTrueColorAlpha (r, g, b, a);
	}

	for (c = 0; c < im->colorsTotal; c++) {
		if (im->open[c]) {
			op = c;		/* Save open slot */
			continue;		/* Color not in use */
		}
		if (c == im->transparent) {
			/* don't ever resolve to the color that has
			 * been designated as the transparent color */
			continue;
		}
		rd = (long) (im->red[c] - r);
		gd = (long) (im->green[c] - g);
		bd = (long) (im->blue[c] - b);
		ad = (long) (im->alpha[c] - a);
		dist = rd * rd + gd * gd + bd * bd + ad * ad;
		if (dist < mindist) {
			if (dist == 0) {
				return c;		/* Return exact match color */
			}
			mindist = dist;
			ct = c;
		}
	}
	/* no exact match.  We now know closest, but first try to allocate exact */
	if (op == -1) {
		op = im->colorsTotal;
		if (op == gdMaxColors) {
			/* No room for more colors */
			return ct;		/* Return closest available color */
		}
		im->colorsTotal++;
	}
	im->red[op] = r;
	im->green[op] = g;
	im->blue[op] = b;
	im->alpha[op] = a;
	im->open[op] = 0;
	return op;			/* Return newly allocated color */
}

BGD_DECLARE(void) gdImageColorDeallocate (gdImagePtr im, int color)
{
	if (im->trueColor || (color >= gdMaxColors) || (color < 0)) {
		return;
	}
	/* Mark it open. */
	im->open[color] = 1;
}

BGD_DECLARE(void) gdImageColorTransparent (gdImagePtr im, int color)
{
	if (!im->trueColor) {
		if((color < -1) || (color >= gdMaxColors)) {
			return;
		}
		if (im->transparent != -1) {
			im->alpha[im->transparent] = gdAlphaOpaque;
		}
		if (color != -1) {
			im->alpha[color] = gdAlphaTransparent;
		}
	}
	im->transparent = color;
}

BGD_DECLARE(void) gdImagePaletteCopy (gdImagePtr to, gdImagePtr from)
{
	int i;
	int x, y, p;
	int xlate[256];
	if (to->trueColor) {
		return;
	}
	if (from->trueColor) {
		return;
	}

	for (i = 0; i < 256; i++) {
		xlate[i] = -1;
	};

	for (y = 0; y < (to->sy); y++) {
		for (x = 0; x < (to->sx); x++) {
			/* Optimization: no gdImageGetPixel */
			p = to->pixels[y][x];
			if (xlate[p] == -1) {
				/* This ought to use HWB, but we don't have an alpha-aware
				   version of that yet. */
				xlate[p] =
				    gdImageColorClosestAlpha (from, to->red[p], to->green[p],
				                              to->blue[p], to->alpha[p]);
				/*printf("Mapping %d (%d, %d, %d, %d) to %d (%d, %d, %d, %d)\n", */
				/*      p,  to->red[p], to->green[p], to->blue[p], to->alpha[p], */
				/*      xlate[p], from->red[xlate[p]], from->green[xlate[p]], from->blue[xlate[p]], from->alpha[xlate[p]]); */
			};
			/* Optimization: no gdImageSetPixel */
			to->pixels[y][x] = xlate[p];
		};
	};

	for (i = 0; (i < (from->colorsTotal)); i++) {
		/*printf("Copying color %d (%d, %d, %d, %d)\n", i, from->red[i], from->blue[i], from->green[i], from->alpha[i]); */
		to->red[i] = from->red[i];
		to->blue[i] = from->blue[i];
		to->green[i] = from->green[i];
		to->alpha[i] = from->alpha[i];
		to->open[i] = 0;
	};

	for (i = from->colorsTotal; (i < to->colorsTotal); i++) {
		to->open[i] = 1;
	};

	to->colorsTotal = from->colorsTotal;

}

BGD_DECLARE(int) gdImageColorReplace (gdImagePtr im, int src, int dst)
{
	register int x, y;
	int n = 0;

	if (src == dst) {
		return 0;
	}

#define REPLACING_LOOP(pixel) do {								\
		for (y = im->cy1; y <= im->cy2; y++) {					\
			for (x = im->cx1; x <= im->cx2; x++) {				\
				if (pixel(im, x, y) == src) {					\
					gdImageSetPixel(im, x, y, dst);				\
					n++;										\
				}												\
			}													\
		}														\
	} while (0)

	if (im->trueColor) {
		REPLACING_LOOP(gdImageTrueColorPixel);
	} else {
		REPLACING_LOOP(gdImagePalettePixel);
	}

#undef REPLACING_LOOP

	return n;
}

BGD_DECLARE(int) gdImageColorReplaceThreshold (gdImagePtr im, int src, int dst, float threshold)
{
	register int x, y;
	int n = 0;

	if (src == dst) {
		return 0;
	}

#define REPLACING_LOOP(pixel) do {										\
		for (y = im->cy1; y <= im->cy2; y++) {							\
			for (x = im->cx1; x <= im->cx2; x++) {						\
				if (gdColorMatch(im, src, pixel(im, x, y), threshold)) { \
					gdImageSetPixel(im, x, y, dst);						\
					n++;												\
				}														\
			}															\
		}																\
	} while (0)

	if (im->trueColor) {
		REPLACING_LOOP(gdImageTrueColorPixel);
	} else {
		REPLACING_LOOP(gdImagePalettePixel);
	}

#undef REPLACING_LOOP

	return n;
}

static int __cdecl colorCmp (const void *x, const void *y)
{
	int a = *(int const *)x;
	int b = *(int const *)y;
	return (a > b) - (a < b);
}

BGD_DECLARE(int) gdImageColorReplaceArray (gdImagePtr im, int len, int *src, int *dst)
{
	register int x, y;
	int c, *d, *base;
	int i, n = 0;

	if (len <= 0 || src == dst) {
		return 0;
	}
	if (len == 1) {
		return gdImageColorReplace(im, src[0], dst[0]);
	}
	if (overflow2(len, sizeof(int)<<1)) {
		return -1;
	}
	base = (int *)gdMalloc(len * (sizeof(int)<<1));
	if (!base) {
		return -1;
	}
	for (i = 0; i < len; i++) {
		base[(i<<1)]   = src[i];
		base[(i<<1)+1] = dst[i];
	}
	qsort(base, len, sizeof(int)<<1, colorCmp);

#define REPLACING_LOOP(pixel) do {										\
		for (y = im->cy1; y <= im->cy2; y++) {							\
			for (x = im->cx1; x <= im->cx2; x++) {						\
				c = pixel(im, x, y);									\
				if ( (d = (int *)bsearch(&c, base, len, sizeof(int)<<1, colorCmp)) ) { \
					gdImageSetPixel(im, x, y, d[1]);					\
					n++;												\
				}														\
			}															\
		}																\
	} while (0)

	if (im->trueColor) {
		REPLACING_LOOP(gdImageTrueColorPixel);
	} else {
		REPLACING_LOOP(gdImagePalettePixel);
	}

#undef REPLACING_LOOP

	gdFree(base);
	return n;
}

BGD_DECLARE(int) gdImageColorReplaceCallback (gdImagePtr im, gdCallbackImageColor callback)
{
	int c, d, n = 0;

	if (!callback) {
		return 0;
	}
	if (im->trueColor) {
		register int x, y;

		for (y = im->cy1; y <= im->cy2; y++) {
			for (x = im->cx1; x <= im->cx2; x++) {
				c = gdImageTrueColorPixel(im, x, y);
				if ( (d = callback(im, c)) != c) {
					gdImageSetPixel(im, x, y, d);
					n++;
				}
			}
		}
	} else { /* palette */
		int *sarr, *darr;
		int k, len = 0;

		sarr = (int *)gdCalloc(im->colorsTotal, sizeof(int));
		if (!sarr) {
			return -1;
		}
		for (c = 0; c < im->colorsTotal; c++) {
			if (!im->open[c]) {
				sarr[len++] = c;
			}
		}
		darr = (int *)gdCalloc(len, sizeof(int));
		if (!darr) {
			gdFree(sarr);
			return -1;
		}
		for (k = 0; k < len; k++) {
			darr[k] = callback(im, sarr[k]);
		}
		n = gdImageColorReplaceArray(im, k, sarr, darr);
		gdFree(darr);
		gdFree(sarr);
	}
	return n;
}

/* 2.0.10: before the drawing routines, some code to clip points that are
 * outside the drawing window.  Nick Atty (nick@canalplan.org.uk)
 *
 * This is the Sutherland Hodgman Algorithm, as implemented by
 * Duvanenko, Robbins and Gyurcsik - SH(DRG) for short.  See Dr Dobb's
 * Journal, January 1996, pp107-110 and 116-117
 *
 * Given the end points of a line, and a bounding rectangle (which we
 * know to be from (0,0) to (SX,SY)), adjust the endpoints to be on
 * the edges of the rectangle if the line should be drawn at all,
 * otherwise return a failure code */

/* this does "one-dimensional" clipping: note that the second time it
   is called, all the x parameters refer to height and the y to width
   - the comments ignore this (if you can understand it when it's
   looking at the X parameters, it should become clear what happens on
   the second call!)  The code is simplified from that in the article,
   as we know that gd images always start at (0,0) */

/* 2.0.26, TBB: we now have to respect a clipping rectangle, it won't
	necessarily start at 0. */

static int
clip_1d (int *x0, int *y0, int *x1, int *y1, int mindim, int maxdim)
{
	double m;			/* gradient of line */
	if (*x0 < mindim) {
		/* start of line is left of window */
		if (*x1 < mindim)		/* as is the end, so the line never cuts the window */
			return 0;
		m = (*y1 - *y0) / (double) (*x1 - *x0);	/* calculate the slope of the line */
		/* adjust x0 to be on the left boundary (ie to be zero), and y0 to match */
		*y0 -= (int)(m * (*x0 - mindim));
		*x0 = mindim;
		/* now, perhaps, adjust the far end of the line as well */
		if (*x1 > maxdim) {
			*y1 += m * (maxdim - *x1);
			*x1 = maxdim;
		}
		return 1;
	}
	if (*x0 > maxdim) {
		/* start of line is right of window -
		complement of above */
		if (*x1 > maxdim)		/* as is the end, so the line misses the window */
			return 0;
		m = (*y1 - *y0) / (double) (*x1 - *x0);	/* calculate the slope of the line */
		*y0 += (int)(m * (maxdim - *x0));	/* adjust so point is on the right
							   boundary */
		*x0 = maxdim;
		/* now, perhaps, adjust the end of the line */
		if (*x1 < mindim) {
			*y1 -= (int)(m * (*x1 - mindim));
			*x1 = mindim;
		}
		return 1;
	}
	/* the final case - the start of the line is inside the window */
	if (*x1 > maxdim) {
		/* other end is outside to the right */
		m = (*y1 - *y0) / (double) (*x1 - *x0);	/* calculate the slope of the line */
		*y1 += (int)(m * (maxdim - *x1));
		*x1 = maxdim;
		return 1;
	}
	if (*x1 < mindim) {
		/* other end is outside to the left */
		m = (*y1 - *y0) / (double) (*x1 - *x0);	/* calculate the slope of the line */
		*y1 -= (int)(m * (*x1 - mindim));
		*x1 = mindim;
		return 1;
	}
	/* only get here if both points are inside the window */
	return 1;
}

/* end of line clipping code */

BGD_DECLARE(void) gdImageSetPixel (gdImagePtr im, int x, int y, int color)
{
	int p;
	switch (color) {
	case gdStyled:
		if (!im->style) {
			/* Refuse to draw if no style is set. */
			return;
		} else {
			p = im->style[im->stylePos++];
		}
		if (p != (gdTransparent)) {
			gdImageSetPixel (im, x, y, p);
		}
		im->stylePos = im->stylePos % im->styleLength;
		break;
	case gdStyledBrushed:
		if (!im->style) {
			/* Refuse to draw if no style is set. */
			return;
		}
		p = im->style[im->stylePos++];
		if ((p != gdTransparent) && (p != 0)) {
			gdImageSetPixel (im, x, y, gdBrushed);
		}
		im->stylePos = im->stylePos % im->styleLength;
		break;
	case gdBrushed:
		gdImageBrushApply (im, x, y);
		break;
	case gdTiled:
		gdImageTileApply (im, x, y);
		break;
	case gdAntiAliased:
		/* This shouldn't happen (2.0.26) because we just call
		  gdImageAALine now, but do something sane. */
		gdImageSetPixel(im, x, y, im->AA_color);
		break;
	default:
		if (gdImageBoundsSafeMacro (im, x, y)) {
			if (im->trueColor) {
				if (im->alphaBlendingFlag) {
					im->tpixels[y][x] = gdAlphaBlend (im->tpixels[y][x], color);
				} else {
					im->tpixels[y][x] = color;
				}
			} else {
				im->pixels[y][x] = color;
			}
		}
		break;
	}
}

static void
gdImageBrushApply (gdImagePtr im, int x, int y)
{
	int lx, ly;
	int hy;
	int hx;
	int x1, y1, x2, y2;
	int srcx, srcy;
	if (!im->brush) {
		return;
	}
	hy = gdImageSY (im->brush) / 2;
	y1 = y - hy;
	y2 = y1 + gdImageSY (im->brush);
	hx = gdImageSX (im->brush) / 2;
	x1 = x - hx;
	x2 = x1 + gdImageSX (im->brush);
	srcy = 0;
	if (im->trueColor) {
		if (im->brush->trueColor) {
			for (ly = y1; (ly < y2); ly++) {
				srcx = 0;
				for (lx = x1; (lx < x2); lx++) {
					int p;
					p = gdImageGetTrueColorPixel (im->brush, srcx, srcy);
					/* 2.0.9, Thomas Winzig: apply simple full transparency */
					if (p != gdImageGetTransparent (im->brush)) {
						gdImageSetPixel (im, lx, ly, p);
					}
					srcx++;
				}
				srcy++;
			}
		} else {
			/* 2.0.12: Brush palette, image truecolor (thanks to Thorben Kundinger
			   for pointing out the issue) */
			for (ly = y1; (ly < y2); ly++) {
				srcx = 0;
				for (lx = x1; (lx < x2); lx++) {
					int p, tc;
					p = gdImageGetPixel (im->brush, srcx, srcy);
					tc = gdImageGetTrueColorPixel (im->brush, srcx, srcy);
					/* 2.0.9, Thomas Winzig: apply simple full transparency */
					if (p != gdImageGetTransparent (im->brush)) {
						gdImageSetPixel (im, lx, ly, tc);
					}
					srcx++;
				}
				srcy++;
			}
		}
	} else {
		for (ly = y1; (ly < y2); ly++) {
			srcx = 0;
			for (lx = x1; (lx < x2); lx++) {
				int p;
				p = gdImageGetPixel (im->brush, srcx, srcy);
				/* Allow for non-square brushes! */
				if (p != gdImageGetTransparent (im->brush)) {
					/* Truecolor brush. Very slow
					   on a palette destination. */
					if (im->brush->trueColor) {
						gdImageSetPixel (im, lx, ly,
						                 gdImageColorResolveAlpha (im,
						                         gdTrueColorGetRed
						                         (p),
						                         gdTrueColorGetGreen
						                         (p),
						                         gdTrueColorGetBlue
						                         (p),
						                         gdTrueColorGetAlpha
						                         (p)));
					} else {
						gdImageSetPixel (im, lx, ly, im->brushColorMap[p]);
					}
				}
				srcx++;
			}
			srcy++;
		}
	}
}

static void
gdImageTileApply (gdImagePtr im, int x, int y)
{
	gdImagePtr tile = im->tile;
	int srcx, srcy;
	int p;
	if (!tile) {
		return;
	}
	srcx = x % gdImageSX (tile);
	srcy = y % gdImageSY (tile);
	if (im->trueColor) {
		p = gdImageGetPixel (tile, srcx, srcy);
		if (p != gdImageGetTransparent (tile)) {
			if (!tile->trueColor) {
				p = gdTrueColorAlpha(tile->red[p], tile->green[p], tile->blue[p], tile->alpha[p]);
			}
			gdImageSetPixel (im, x, y, p);
		}
	} else {
		p = gdImageGetPixel (tile, srcx, srcy);
		/* Allow for transparency */
		if (p != gdImageGetTransparent (tile)) {
			if (tile->trueColor) {
				/* Truecolor tile. Very slow
				   on a palette destination. */
				gdImageSetPixel (im, x, y,
				                 gdImageColorResolveAlpha (im,
				                         gdTrueColorGetRed
				                         (p),
				                         gdTrueColorGetGreen
				                         (p),
				                         gdTrueColorGetBlue
				                         (p),
				                         gdTrueColorGetAlpha
				                         (p)));
			} else {
				gdImageSetPixel (im, x, y, im->tileColorMap[p]);
			}
		}
	}
}

BGD_DECLARE(int) gdImageGetPixel (gdImagePtr im, int x, int y)
{
	if (gdImageBoundsSafeMacro (im, x, y)) {
		if (im->trueColor) {
			return im->tpixels[y][x];
		} else {
			return im->pixels[y][x];
		}
	} else {
		return 0;
	}
}

BGD_DECLARE(int) gdImageGetTrueColorPixel (gdImagePtr im, int x, int y)
{
	int p = gdImageGetPixel (im, x, y);
	if (!im->trueColor) {
		return gdTrueColorAlpha (im->red[p], im->green[p], im->blue[p],
		                         (im->transparent == p) ? gdAlphaTransparent :
		                         im->alpha[p]);
	} else {
		return p;
	}
}

BGD_DECLARE(void) gdImageAABlend (gdImagePtr im)
{
	/* NO-OP, kept for library compatibility. */
	(void)im;
}

static void gdImageAALine (gdImagePtr im, int x1, int y1, int x2, int y2, int col);

static void gdImageHLine(gdImagePtr im, int y, int x1, int x2, int col)
{
	if (im->thick > 1) {
		int thickhalf = im->thick >> 1;
		gdImageFilledRectangle(im, x1, y - thickhalf, x2, y + im->thick - thickhalf - 1, col);
	} else {
		if (x2 < x1) {
			int t = x2;
			x2 = x1;
			x1 = t;
		}

		for (; x1 <= x2; x1++) {
			gdImageSetPixel(im, x1, y, col);
		}
	}
	return;
}

static void gdImageVLine(gdImagePtr im, int x, int y1, int y2, int col)
{
	if (im->thick > 1) {
		int thickhalf = im->thick >> 1;
		gdImageFilledRectangle(im, x - thickhalf, y1, x + im->thick - thickhalf - 1, y2, col);
	} else {
		if (y2 < y1) {
			int t = y1;
			y1 = y2;
			y2 = t;
		}

		for (; y1 <= y2; y1++) {
			gdImageSetPixel(im, x, y1, col);
		}
	}
	return;
}

/* Bresenham as presented in Foley & Van Dam */
BGD_DECLARE(void) gdImageLine (gdImagePtr im, int x1, int y1, int x2, int y2, int color)
{
	int dx, dy, incr1, incr2, d, x, y, xend, yend, xdirflag, ydirflag;
	int wid;
	int w, wstart;
	int thick;

	if (color == gdAntiAliased) {
		/*
		  gdAntiAliased passed as color: use the much faster, much cheaper
		  and equally attractive gdImageAALine implementation. That
		  clips too, so don't clip twice.
		*/
		gdImageAALine(im, x1, y1, x2, y2, im->AA_color);
		return;
	}
	/* 2.0.10: Nick Atty: clip to edges of drawing rectangle, return if no
	   points need to be drawn. 2.0.26, TBB: clip to edges of clipping
	   rectangle. We were getting away with this because gdImageSetPixel
	   is used for actual drawing, but this is still more efficient and opens
	   the way to skip per-pixel bounds checking in the future. */

	if (clip_1d (&x1, &y1, &x2, &y2, im->cx1, im->cx2) == 0)
		return;
	if (clip_1d (&y1, &x1, &y2, &x2, im->cy1, im->cy2) == 0)
		return;
	thick = im->thick;

	dx = abs (x2 - x1);
	dy = abs (y2 - y1);

	if (dx == 0) {
		gdImageVLine(im, x1, y1, y2, color);
		return;
	} else if (dy == 0) {
		gdImageHLine(im, y1, x1, x2, color);
		return;
	}

	if (dy <= dx) {
		/* More-or-less horizontal. use wid for vertical stroke */
		/* Doug Claar: watch out for NaN in atan2 (2.0.5) */
		if ((dx == 0) && (dy == 0)) {
			wid = 1;
		} else {
			/* 2.0.12: Michael Schwartz: divide rather than multiply;
			   TBB: but watch out for /0! */
			double ac = cos (atan2 (dy, dx));
			if (ac != 0) {
				wid = thick / ac;
			} else {
				wid = 1;
			}
			if (wid == 0) {
				wid = 1;
			}
		}
		d = 2 * dy - dx;
		incr1 = 2 * dy;
		incr2 = 2 * (dy - dx);
		if (x1 > x2) {
			x = x2;
			y = y2;
			ydirflag = (-1);
			xend = x1;
		} else {
			x = x1;
			y = y1;
			ydirflag = 1;
			xend = x2;
		}

		/* Set up line thickness */
		wstart = y - wid / 2;
		for (w = wstart; w < wstart + wid; w++)
			gdImageSetPixel (im, x, w, color);

		if (((y2 - y1) * ydirflag) > 0) {
			while (x < xend) {
				x++;
				if (d < 0) {
					d += incr1;
				} else {
					y++;
					d += incr2;
				}
				wstart = y - wid / 2;
				for (w = wstart; w < wstart + wid; w++)
					gdImageSetPixel (im, x, w, color);
			}
		} else {
			while (x < xend) {
				x++;
				if (d < 0) {
					d += incr1;
				} else {
					y--;
					d += incr2;
				}
				wstart = y - wid / 2;
				for (w = wstart; w < wstart + wid; w++)
					gdImageSetPixel (im, x, w, color);
			}
		}
	} else {
		/* More-or-less vertical. use wid for horizontal stroke */
		/* 2.0.12: Michael Schwartz: divide rather than multiply;
		   TBB: but watch out for /0! */
		double as = sin (atan2 (dy, dx));
		if (as != 0) {
			wid = thick / as;
		} else {
			wid = 1;
		}
		if (wid == 0)
			wid = 1;

		d = 2 * dx - dy;
		incr1 = 2 * dx;
		incr2 = 2 * (dx - dy);
		if (y1 > y2) {
			y = y2;
			x = x2;
			yend = y1;
			xdirflag = (-1);
		} else {
			y = y1;
			x = x1;
			yend = y2;
			xdirflag = 1;
		}

		/* Set up line thickness */
		wstart = x - wid / 2;
		for (w = wstart; w < wstart + wid; w++)
			gdImageSetPixel (im, w, y, color);

		if (((x2 - x1) * xdirflag) > 0) {
			while (y < yend) {
				y++;
				if (d < 0) {
					d += incr1;
				} else {
					x++;
					d += incr2;
				}
				wstart = x - wid / 2;
				for (w = wstart; w < wstart + wid; w++)
					gdImageSetPixel (im, w, y, color);
			}
		} else {
			while (y < yend) {
				y++;
				if (d < 0) {
					d += incr1;
				} else {
					x--;
					d += incr2;
				}
				wstart = x - wid / 2;
				for (w = wstart; w < wstart + wid; w++)
					gdImageSetPixel (im, w, y, color);
			}
		}
	}

}
static void dashedSet (gdImagePtr im, int x, int y, int color,
					   int *onP, int *dashStepP, int wid, int vert);

BGD_DECLARE(void) gdImageDashedLine (gdImagePtr im, int x1, int y1, int x2, int y2, int color)
{
	int dx, dy, incr1, incr2, d, x, y, xend, yend, xdirflag, ydirflag;
	int dashStep = 0;
	int on = 1;
	int wid;
	int vert;
	int thick = im->thick;

	dx = abs (x2 - x1);
	dy = abs (y2 - y1);
	if (dy <= dx) {
		/* More-or-less horizontal. use wid for vertical stroke */
		/* 2.0.12: Michael Schwartz: divide rather than multiply;
		   TBB: but watch out for /0! */
		double as = sin (atan2 (dy, dx));
		if (as != 0) {
			wid = thick / as;
		} else {
			wid = 1;
		}
		vert = 1;

		d = 2 * dy - dx;
		incr1 = 2 * dy;
		incr2 = 2 * (dy - dx);
		if (x1 > x2) {
			x = x2;
			y = y2;
			ydirflag = (-1);
			xend = x1;
		} else {
			x = x1;
			y = y1;
			ydirflag = 1;
			xend = x2;
		}
		dashedSet (im, x, y, color, &on, &dashStep, wid, vert);
		if (((y2 - y1) * ydirflag) > 0) {
			while (x < xend) {
				x++;
				if (d < 0) {
					d += incr1;
				} else {
					y++;
					d += incr2;
				}
				dashedSet (im, x, y, color, &on, &dashStep, wid, vert);
			}
		} else {
			while (x < xend) {
				x++;
				if (d < 0) {
					d += incr1;
				} else {
					y--;
					d += incr2;
				}
				dashedSet (im, x, y, color, &on, &dashStep, wid, vert);
			}
		}
	} else {
		/* 2.0.12: Michael Schwartz: divide rather than multiply;
		   TBB: but watch out for /0! */
		double as = sin (atan2 (dy, dx));
		if (as != 0) {
			wid = thick / as;
		} else {
			wid = 1;
		}
		vert = 0;

		d = 2 * dx - dy;
		incr1 = 2 * dx;
		incr2 = 2 * (dx - dy);
		if (y1 > y2) {
			y = y2;
			x = x2;
			yend = y1;
			xdirflag = (-1);
		} else {
			y = y1;
			x = x1;
			yend = y2;
			xdirflag = 1;
		}
		dashedSet (im, x, y, color, &on, &dashStep, wid, vert);
		if (((x2 - x1) * xdirflag) > 0) {
			while (y < yend) {
				y++;
				if (d < 0) {
					d += incr1;
				} else {
					x++;
					d += incr2;
				}
				dashedSet (im, x, y, color, &on, &dashStep, wid, vert);
			}
		} else {
			while (y < yend) {
				y++;
				if (d < 0) {
					d += incr1;
				} else {
					x--;
					d += incr2;
				}
				dashedSet (im, x, y, color, &on, &dashStep, wid, vert);
			}
		}
	}
}

static void
dashedSet (gdImagePtr im, int x, int y, int color,
		   int *onP, int *dashStepP, int wid, int vert)
{
	int dashStep = *dashStepP;
	int on = *onP;
	int w, wstart;

	dashStep++;
	if (dashStep == gdDashSize) {
		dashStep = 0;
		on = !on;
	}
	if (on) {
		if (vert) {
			wstart = y - wid / 2;
			for (w = wstart; w < wstart + wid; w++)
				gdImageSetPixel (im, x, w, color);
		} else {
			wstart = x - wid / 2;
			for (w = wstart; w < wstart + wid; w++)
				gdImageSetPixel (im, w, y, color);
		}
	}
	*dashStepP = dashStep;
	*onP = on;
}

BGD_DECLARE(int) gdImageBoundsSafe (gdImagePtr im, int x, int y)
{
	return gdImageBoundsSafeMacro (im, x, y);
}

BGD_DECLARE(void) gdImageChar (gdImagePtr im, gdFontPtr f, int x, int y, int c, int color)
{
	int cx, cy;
	int px, py;
	int fline;
	cx = 0;
	cy = 0;
#ifdef CHARSET_EBCDIC
	c = ASC (c);
#endif /*CHARSET_EBCDIC */
	if ((c < f->offset) || (c >= (f->offset + f->nchars))) {
		return;
	}
	fline = (c - f->offset) * f->h * f->w;
	for (py = y; (py < (y + f->h)); py++) {
		for (px = x; (px < (x + f->w)); px++) {
			if (f->data[fline + cy * f->w + cx]) {
				gdImageSetPixel (im, px, py, color);
			}
			cx++;
		}
		cx = 0;
		cy++;
	}
}

BGD_DECLARE(void) gdImageCharUp (gdImagePtr im, gdFontPtr f, int x, int y, int c, int color)
{
	int cx, cy;
	int px, py;
	int fline;
	cx = 0;
	cy = 0;
#ifdef CHARSET_EBCDIC
	c = ASC (c);
#endif /*CHARSET_EBCDIC */
	if ((c < f->offset) || (c >= (f->offset + f->nchars))) {
		return;
	}
	fline = (c - f->offset) * f->h * f->w;
	for (py = y; (py > (y - f->w)); py--) {
		for (px = x; (px < (x + f->h)); px++) {
			if (f->data[fline + cy * f->w + cx]) {
				gdImageSetPixel (im, px, py, color);
			}
			cy++;
		}
		cy = 0;
		cx++;
	}
}

BGD_DECLARE(void) gdImageString (gdImagePtr im, gdFontPtr f,
								 int x, int y, unsigned char *s, int color)
{
	int i;
	int l;
	l = strlen ((char *) s);
	for (i = 0; (i < l); i++) {
		gdImageChar (im, f, x, y, s[i], color);
		x += f->w;
	}
}

BGD_DECLARE(void) gdImageStringUp (gdImagePtr im, gdFontPtr f,
								   int x, int y, unsigned char *s, int color)
{
	int i;
	int l;
	l = strlen ((char *) s);
	for (i = 0; (i < l); i++) {
		gdImageCharUp (im, f, x, y, s[i], color);
		y -= f->w;
	}
}

static int strlen16 (unsigned short *s);

BGD_DECLARE(void) gdImageString16 (gdImagePtr im, gdFontPtr f,
								   int x, int y, unsigned short *s, int color)
{
	int i;
	int l;
	l = strlen16 (s);
	for (i = 0; (i < l); i++) {
		gdImageChar (im, f, x, y, s[i], color);
		x += f->w;
	}
}

BGD_DECLARE(void) gdImageStringUp16 (gdImagePtr im, gdFontPtr f,
									 int x, int y, unsigned short *s, int color)
{
	int i;
	int l;
	l = strlen16 (s);
	for (i = 0; (i < l); i++) {
		gdImageCharUp (im, f, x, y, s[i], color);
		y -= f->w;
	}
}

static int
strlen16 (unsigned short *s)
{
	int len = 0;
	while (*s) {
		s++;
		len++;
	}
	return len;
}

#ifndef HAVE_LSQRT
/* If you don't have a nice square root function for longs, you can use
   ** this hack
 */
long
lsqrt (long n)
{
	long result = (long) sqrt ((double) n);
	return result;
}
#endif

/* s and e are integers modulo 360 (degrees), with 0 degrees
   being the rightmost extreme and degrees changing clockwise.
   cx and cy are the center in pixels; w and h are the horizontal
   and vertical diameter in pixels. Nice interface, but slow.
   See gd_arc_f_buggy.c for a better version that doesn't
   seem to be bug-free yet. */

BGD_DECLARE(void) gdImageArc (gdImagePtr im, int cx, int cy, int w, int h, int s, int e,
							  int color)
{
	gdImageFilledArc (im, cx, cy, w, h, s, e, color, gdNoFill);
}

BGD_DECLARE(void) gdImageFilledArc (gdImagePtr im, int cx, int cy, int w, int h, int s, int e,
									int color, int style)
{
	gdPoint pts[3];
	int i;
	int lx = 0, ly = 0;
	int fx = 0, fy = 0;

	if ((s % 360)  == (e % 360)) {
		s = 0;
		e = 360;
	} else {
		if (s > 360) {
			s = s % 360;
		}

		if (e > 360) {
			e = e % 360;
		}

		while (s < 0) {
			s += 360;
		}

		while (e < s) {
			e += 360;
		}

		if (s == e) {
			s = 0;
			e = 360;
		}
	}

	for (i = s; (i <= e); i++) {
		int x, y;
		x = ((long) gdCosT[i % 360] * (long) w / (2 * 1024)) + cx;
		y = ((long) gdSinT[i % 360] * (long) h / (2 * 1024)) + cy;
		if (i != s) {
			if (!(style & gdChord)) {
				if (style & gdNoFill) {
					gdImageLine (im, lx, ly, x, y, color);
				} else {
					/* This is expensive! */
					pts[0].x = lx;
					pts[0].y = ly;
					pts[1].x = x;
					pts[1].y = y;
					pts[2].x = cx;
					pts[2].y = cy;
					gdImageFilledPolygon (im, pts, 3, color);
				}
			}
		} else {
			fx = x;
			fy = y;
		}
		lx = x;
		ly = y;
	}
	if (style & gdChord) {
		if (style & gdNoFill) {
			if (style & gdEdged) {
				gdImageLine (im, cx, cy, lx, ly, color);
				gdImageLine (im, cx, cy, fx, fy, color);
			}
			gdImageLine (im, fx, fy, lx, ly, color);
		} else {
			pts[0].x = fx;
			pts[0].y = fy;
			pts[1].x = lx;
			pts[1].y = ly;
			pts[2].x = cx;
			pts[2].y = cy;
			gdImageFilledPolygon (im, pts, 3, color);
		}
	} else {
		if (style & gdNoFill) {
			if (style & gdEdged) {
				gdImageLine (im, cx, cy, lx, ly, color);
				gdImageLine (im, cx, cy, fx, fy, color);
			}
		}
	}
}

BGD_DECLARE(void) gdImageEllipse(gdImagePtr im, int mx, int my, int w, int h, int c)
{
	int x=0,mx1=0,mx2=0,my1=0,my2=0;
	long aq,bq,dx,dy,r,rx,ry,a,b;

	a=w>>1;
	b=h>>1;
	gdImageSetPixel(im,mx+a, my, c);
	gdImageSetPixel(im,mx-a, my, c);
	mx1 = mx-a;
	my1 = my;
	mx2 = mx+a;
	my2 = my;

	aq = a * a;
	bq = b * b;
	dx = aq << 1;
	dy = bq << 1;
	r  = a * bq;
	rx = r << 1;
	ry = 0;
	x = a;
	while (x > 0) {
		if (r > 0) {
			my1++;
			my2--;
			ry +=dx;
			r  -=ry;
		}
		if (r <= 0) {
			x--;
			mx1++;
			mx2--;
			rx -=dy;
			r  +=rx;
		}
		gdImageSetPixel(im,mx1, my1, c);
		gdImageSetPixel(im,mx1, my2, c);
		gdImageSetPixel(im,mx2, my1, c);
		gdImageSetPixel(im,mx2, my2, c);
	}
}


BGD_DECLARE(void) gdImageFilledEllipse (gdImagePtr im, int mx, int my, int w, int h, int c)
{
	int x=0,mx1=0,mx2=0,my1=0,my2=0;
	long aq,bq,dx,dy,r,rx,ry,a,b;
	int i;
	int old_y2;

	a=w>>1;
	b=h>>1;

	for (x = mx-a; x <= mx+a; x++) {
		gdImageSetPixel(im, x, my, c);
	}

	mx1 = mx-a;
	my1 = my;
	mx2 = mx+a;
	my2 = my;

	aq = a * a;
	bq = b * b;
	dx = aq << 1;
	dy = bq << 1;
	r  = a * bq;
	rx = r << 1;
	ry = 0;
	x = a;
	old_y2=-2;
	while (x > 0) {
		if (r > 0) {
			my1++;
			my2--;
			ry +=dx;
			r  -=ry;
		}
		if (r <= 0) {
			x--;
			mx1++;
			mx2--;
			rx -=dy;
			r  +=rx;
		}
		if(old_y2!=my2) {
			for(i=mx1; i<=mx2; i++) {
				gdImageSetPixel(im,i,my1,c);
			}
		}
		if(old_y2!=my2) {
			for(i=mx1; i<=mx2; i++) {
				gdImageSetPixel(im,i,my2,c);
			}
		}
		old_y2 = my2;
	}
}

BGD_DECLARE(void) gdImageFillToBorder (gdImagePtr im, int x, int y, int border, int color)
{
	int lastBorder;
	/* Seek left */
	int leftLimit, rightLimit;
	int i;
	int restoreAlphaBleding;

	if (border < 0) {
		/* Refuse to fill to a non-solid border */
		return;
	}

	leftLimit = (-1);

	restoreAlphaBleding = im->alphaBlendingFlag;
	im->alphaBlendingFlag = 0;

	for (i = x; (i >= 0); i--) {
		if (gdImageGetPixel (im, i, y) == border) {
			break;
		}
		gdImageSetPixel (im, i, y, color);
		leftLimit = i;
	}
	if (leftLimit == (-1)) {
		im->alphaBlendingFlag = restoreAlphaBleding;
		return;
	}
	/* Seek right */
	rightLimit = x;
	for (i = (x + 1); (i < im->sx); i++) {
		if (gdImageGetPixel (im, i, y) == border) {
			break;
		}
		gdImageSetPixel (im, i, y, color);
		rightLimit = i;
	}
	/* Look at lines above and below and start paints */
	/* Above */
	if (y > 0) {
		lastBorder = 1;
		for (i = leftLimit; (i <= rightLimit); i++) {
			int c;
			c = gdImageGetPixel (im, i, y - 1);
			if (lastBorder) {
				if ((c != border) && (c != color)) {
					gdImageFillToBorder (im, i, y - 1, border, color);
					lastBorder = 0;
				}
			} else if ((c == border) || (c == color)) {
				lastBorder = 1;
			}
		}
	}
	/* Below */
	if (y < ((im->sy) - 1)) {
		lastBorder = 1;
		for (i = leftLimit; (i <= rightLimit); i++) {
			int c = gdImageGetPixel (im, i, y + 1);
			if (lastBorder) {
				if ((c != border) && (c != color)) {
					gdImageFillToBorder (im, i, y + 1, border, color);
					lastBorder = 0;
				}
			} else if ((c == border) || (c == color)) {
				lastBorder = 1;
			}
		}
	}
	im->alphaBlendingFlag = restoreAlphaBleding;
}

/*
 * set the pixel at (x,y) and its 4-connected neighbors
 * with the same pixel value to the new pixel value nc (new color).
 * A 4-connected neighbor:  pixel above, below, left, or right of a pixel.
 * ideas from comp.graphics discussions.
 * For tiled fill, the use of a flag buffer is mandatory. As the tile image can
 * contain the same color as the color to fill. To do not bloat normal filling
 * code I added a 2nd private function.
 */

static int gdImageTileGet (gdImagePtr im, int x, int y)
{
	int srcx, srcy;
	int tileColor,p;
	if (!im->tile) {
		return -1;
	}
	srcx = x % gdImageSX(im->tile);
	srcy = y % gdImageSY(im->tile);
	p = gdImageGetPixel(im->tile, srcx, srcy);
	if (p == im->tile->transparent) {
		tileColor = im->transparent;
	} else if (im->trueColor) {
		if (im->tile->trueColor) {
			tileColor = p;
		} else {
			tileColor = gdTrueColorAlpha( gdImageRed(im->tile,p), gdImageGreen(im->tile,p), gdImageBlue (im->tile,p), gdImageAlpha (im->tile,p));
		}
	} else {
		if (im->tile->trueColor) {
			tileColor = gdImageColorResolveAlpha(im, gdTrueColorGetRed (p), gdTrueColorGetGreen (p), gdTrueColorGetBlue (p), gdTrueColorGetAlpha (p));
		} else {
			tileColor = gdImageColorResolveAlpha(im, gdImageRed (im->tile,p), gdImageGreen (im->tile,p), gdImageBlue (im->tile,p), gdImageAlpha (im->tile,p));
		}
	}
	return tileColor;
}



/* horizontal segment of scan line y */
struct seg {
	int y, xl, xr, dy;
};

/* max depth of stack */
#define FILL_MAX ((int)(im->sy*im->sx)/4)
#define FILL_PUSH(Y, XL, XR, DY) \
	if (sp<stack+FILL_MAX && Y+(DY)>=0 && Y+(DY)<wy2) \
	{sp->y = Y; sp->xl = XL; sp->xr = XR; sp->dy = DY; sp++;}

#define FILL_POP(Y, XL, XR, DY) \
	{sp--; Y = sp->y+(DY = sp->dy); XL = sp->xl; XR = sp->xr;}

static void _gdImageFillTiled(gdImagePtr im, int x, int y, int nc);
BGD_DECLARE(void) gdImageFill(gdImagePtr im, int x, int y, int nc)
{
	int l, x1, x2, dy;
	int oc;   /* old pixel value */
	int wx2,wy2;

	int alphablending_bak;

	/* stack of filled segments */
	/* struct seg stack[FILL_MAX],*sp = stack;; */
	struct seg *stack;
	struct seg *sp;

	if (!im->trueColor && nc > (im->colorsTotal - 1)) {
		return;
	}

	alphablending_bak = im->alphaBlendingFlag;
	im->alphaBlendingFlag = 0;

	if (nc==gdTiled) {
		_gdImageFillTiled(im,x,y,nc);
		im->alphaBlendingFlag = alphablending_bak;
		return;
	}

	wx2=im->sx;
	wy2=im->sy;
	oc = gdImageGetPixel(im, x, y);
	if (oc==nc || x<0 || x>wx2 || y<0 || y>wy2) {
		im->alphaBlendingFlag = alphablending_bak;
		return;
	}

	/* Do not use the 4 neighbors implementation with
	* small images
	*/
	if (im->sx < 4) {
		int ix = x, iy = y, c;
		do {
			do {
				c = gdImageGetPixel(im, ix, iy);
				if (c != oc) {
					goto done;
				}
				gdImageSetPixel(im, ix, iy, nc);
			} while(ix++ < (im->sx -1));
			ix = x;
		} while(iy++ < (im->sy -1));
		goto done;
	}

	if(overflow2(im->sy, im->sx)) {
		return;
	}

	if(overflow2(sizeof(struct seg), ((im->sy * im->sx) / 4))) {
		return;
	}

	stack = (struct seg *)gdMalloc(sizeof(struct seg) * ((int)(im->sy*im->sx)/4));
	if (!stack) {
		return;
	}
	sp = stack;

	/* required! */
	FILL_PUSH(y,x,x,1);
	/* seed segment (popped 1st) */
	FILL_PUSH(y+1, x, x, -1);
	while (sp>stack) {
		FILL_POP(y, x1, x2, dy);

		for (x=x1; x>=0 && gdImageGetPixel(im,x, y)==oc; x--) {
			gdImageSetPixel(im,x, y, nc);
		}
		if (x>=x1) {
			goto skip;
		}
		l = x+1;

		/* leak on left? */
		if (l<x1) {
			FILL_PUSH(y, l, x1-1, -dy);
		}
		x = x1+1;
		do {
			for (; x<=wx2 && gdImageGetPixel(im,x, y)==oc; x++) {
				gdImageSetPixel(im, x, y, nc);
			}
			FILL_PUSH(y, l, x-1, dy);
			/* leak on right? */
			if (x>x2+1) {
				FILL_PUSH(y, x2+1, x-1, -dy);
			}
skip:
			for (x++; x<=x2 && (gdImageGetPixel(im, x, y)!=oc); x++);

			l = x;
		} while (x<=x2);
	}

	gdFree(stack);

done:
	im->alphaBlendingFlag = alphablending_bak;
}

static void _gdImageFillTiled(gdImagePtr im, int x, int y, int nc)
{
	int l, x1, x2, dy;
	int oc;   /* old pixel value */
	int wx2,wy2;
	/* stack of filled segments */
	struct seg *stack;
	struct seg *sp;
	char *pts;

	if (!im->tile) {
		return;
	}

	wx2=im->sx;
	wy2=im->sy;

	if(overflow2(im->sy, im->sx)) {
		return;
	}

	if(overflow2(sizeof(struct seg), ((im->sy * im->sx) / 4))) {
		return;
	}

	pts = (char *) gdCalloc(im->sy * im->sx, sizeof(char));
	if (!pts) {
		return;
	}

	stack = (struct seg *)gdMalloc(sizeof(struct seg) * ((int)(im->sy*im->sx)/4));
	if (!stack) {
		gdFree(pts);
		return;
	}
	sp = stack;

	oc = gdImageGetPixel(im, x, y);

	/* required! */
	FILL_PUSH(y,x,x,1);
	/* seed segment (popped 1st) */
	FILL_PUSH(y+1, x, x, -1);
	while (sp>stack) {
		FILL_POP(y, x1, x2, dy);
		for (x=x1; x>=0 && (!pts[y + x*wx2] && gdImageGetPixel(im,x,y)==oc); x--) {
			nc = gdImageTileGet(im,x,y);
			pts[y + x*wx2]=1;
			gdImageSetPixel(im,x, y, nc);
		}
		if (x>=x1) {
			goto skip;
		}
		l = x+1;

		/* leak on left? */
		if (l<x1) {
			FILL_PUSH(y, l, x1-1, -dy);
		}
		x = x1+1;
		do {
			for (; x<wx2 && (!pts[y + x*wx2] && gdImageGetPixel(im,x, y)==oc) ; x++) {
				if (pts[y + x*wx2]) {
					/* we should never be here */
					break;
				}
				nc = gdImageTileGet(im,x,y);
				pts[y + x*wx2]=1;
				gdImageSetPixel(im, x, y, nc);
			}
			FILL_PUSH(y, l, x-1, dy);
			/* leak on right? */
			if (x>x2+1) {
				FILL_PUSH(y, x2+1, x-1, -dy);
			}
skip:
			for (x++; x<=x2 && (pts[y + x*wx2] || gdImageGetPixel(im,x, y)!=oc); x++);
			l = x;
		} while (x<=x2);
	}

	gdFree(pts);
	gdFree(stack);
}

BGD_DECLARE(void) gdImageRectangle (gdImagePtr im, int x1, int y1, int x2, int y2, int color)
{
	int thick = im->thick;

	if (x1 == x2 && y1 == y2 && thick == 1) {
		gdImageSetPixel(im, x1, y1, color);
		return;
	}

	if (y2 < y1) {
		int t;
		t = y1;
		y1 = y2;
		y2 = t;

		t = x1;
		x1 = x2;
		x2 = t;
	}

	if (thick > 1) {
		int cx, cy, x1ul, y1ul, x2lr, y2lr;
		int half = thick >> 1;
		x1ul = x1 - half;
		y1ul = y1 - half;

		x2lr = x2 + half;
		y2lr = y2 + half;

		cy = y1ul + thick;
		while (cy-- > y1ul) {
			cx = x1ul - 1;
			while (cx++ < x2lr) {
				gdImageSetPixel(im, cx, cy, color);
			}
		}

		cy = y2lr - thick;
		while (cy++ < y2lr) {
			cx = x1ul - 1;
			while (cx++ < x2lr) {
				gdImageSetPixel(im, cx, cy, color);
			}
		}

		cy = y1ul + thick - 1;
		while (cy++ < y2lr -thick) {
			cx = x1ul - 1;
			while (cx++ < x1ul + thick) {
				gdImageSetPixel(im, cx, cy, color);
			}
		}

		cy = y1ul + thick - 1;
		while (cy++ < y2lr -thick) {
			cx = x2lr - thick - 1;
			while (cx++ < x2lr) {
				gdImageSetPixel(im, cx, cy, color);
			}
		}

		return;
	} else {
		gdImageLine(im, x1, y1, x2, y1, color);
		gdImageLine(im, x1, y2, x2, y2, color);
		gdImageLine(im, x1, y1 + 1, x1, y2 - 1, color);
		gdImageLine(im, x2, y1 + 1, x2, y2 - 1, color);
	}
}

BGD_DECLARE(void) gdImageFilledRectangle (gdImagePtr im, int x1, int y1, int x2, int y2,
		int color)
{
	int x, y;

	if (x1 == x2 && y1 == y2) {
		gdImageSetPixel(im, x1, y1, color);
		return;
	}

	if (x1 > x2) {
		x = x1;
		x1 = x2;
		x2 = x;
	}

	if (y1 > y2) {
		y = y1;
		y1 = y2;
		y2 = y;
	}

	if (x1 < 0) {
		x1 = 0;
	}

	if (x2 >= gdImageSX(im)) {
		x2 = gdImageSX(im) - 1;
	}

	if (y1 < 0) {
		y1 = 0;
	}

	if (y2 >= gdImageSY(im)) {
		y2 = gdImageSY(im) - 1;
	}

	for (y = y1; (y <= y2); y++) {
		for (x = x1; (x <= x2); x++) {
			gdImageSetPixel (im, x, y, color);
		}
	}
}

BGD_DECLARE(gdImagePtr) gdImageClone (gdImagePtr src) {
	gdImagePtr dst;
	register int i, x;

	if (src->trueColor) {
		dst = gdImageCreateTrueColor(src->sx , src->sy);
	} else {
		dst = gdImageCreate(src->sx , src->sy);
	}

	if (dst == NULL) {
		return NULL;
	}

	if (src->trueColor == 0) {
		dst->colorsTotal = src->colorsTotal;
		for (i = 0; i < gdMaxColors; i++) {
			dst->red[i]   = src->red[i];
			dst->green[i] = src->green[i];
			dst->blue[i]  = src->blue[i];
			dst->alpha[i] = src->alpha[i];
			dst->open[i]  = src->open[i];
		}
		for (i = 0; i < src->sy; i++) {
			for (x = 0; x < src->sx; x++) {
				dst->pixels[i][x] = dst->pixels[i][x];
			}
		}
	} else {
		for (i = 0; i < src->sy; i++) {
			for (x = 0; x < src->sx; x++) {
				dst->tpixels[i][x] = src->tpixels[i][x];
			}
		}
	}

	if (src->styleLength > 0) {
		dst->styleLength = src->styleLength;
		dst->stylePos    = src->stylePos;
		for (i = 0; i < src->styleLength; i++) {
			dst->style[i] = src->style[i];
		}
	}

	dst->interlace   = src->interlace;

	dst->alphaBlendingFlag = src->alphaBlendingFlag;
	dst->saveAlphaFlag     = src->saveAlphaFlag;
	dst->AA                = src->AA;
	dst->AA_color          = src->AA_color;
	dst->AA_dont_blend     = src->AA_dont_blend;

	dst->cx1 = src->cx1;
	dst->cy1 = src->cy1;
	dst->cx2 = src->cx2;
	dst->cy2 = src->cy2;

	dst->res_x = src->res_x;
	dst->res_y = src->res_x;

	dst->paletteQuantizationMethod     = src->paletteQuantizationMethod;
	dst->paletteQuantizationSpeed      = src->paletteQuantizationSpeed;
	dst->paletteQuantizationMinQuality = src->paletteQuantizationMinQuality;
	dst->paletteQuantizationMinQuality = src->paletteQuantizationMinQuality;

	dst->interpolation_id = src->interpolation_id;
	dst->interpolation    = src->interpolation;

	if (src->brush) {
		dst->brush = gdImageClone(src->brush);
	}

	if (src->tile) {
		dst->tile = gdImageClone(src->tile);
	}

	if (src->style) {
		gdImageSetStyle(dst, src->style, src->styleLength);
	}

	for (i = 0; i < gdMaxColors; i++) {
		dst->brushColorMap[i] = src->brushColorMap[i];
		dst->tileColorMap[i] = src->tileColorMap[i];
	}

	if (src->polyAllocated > 0) {
		dst->polyAllocated = src->polyAllocated;
		for (i = 0; i < src->polyAllocated; i++) {
			dst->polyInts[i] = src->polyInts[i];
		}
	}

	return dst;
}

BGD_DECLARE(void) gdImageCopy (gdImagePtr dst, gdImagePtr src, int dstX, int dstY, int srcX,
							   int srcY, int w, int h)
{
	int c;
	int x, y;
	int tox, toy;
	int i;
	int colorMap[gdMaxColors];

	if (dst->trueColor) {
		/* 2.0: much easier when the destination is truecolor. */
		/* 2.0.10: needs a transparent-index check that is still valid if
		 *          * the source is not truecolor. Thanks to Frank Warmerdam.
		 */

		if (src->trueColor) {
			for (y = 0; (y < h); y++) {
				for (x = 0; (x < w); x++) {
					int c = gdImageGetTrueColorPixel (src, srcX + x, srcY + y);
					if (c != src->transparent) {
						gdImageSetPixel (dst, dstX + x, dstY + y, c);
					}
				}
			}
		} else {
			/* source is palette based */
			for (y = 0; (y < h); y++) {
				for (x = 0; (x < w); x++) {
					int c = gdImageGetPixel (src, srcX + x, srcY + y);
					if (c != src->transparent) {
						gdImageSetPixel(dst, dstX + x, dstY + y, gdTrueColorAlpha(src->red[c], src->green[c], src->blue[c], src->alpha[c]));
					}
				}
			}
		}
		return;
	}

	for (i = 0; (i < gdMaxColors); i++) {
		colorMap[i] = (-1);
	}
	toy = dstY;
	for (y = srcY; (y < (srcY + h)); y++) {
		tox = dstX;
		for (x = srcX; (x < (srcX + w)); x++) {
			int nc;
			int mapTo;
			c = gdImageGetPixel (src, x, y);
			/* Added 7/24/95: support transparent copies */
			if (gdImageGetTransparent (src) == c) {
				tox++;
				continue;
			}
			/* Have we established a mapping for this color? */
			if (src->trueColor) {
				/* 2.05: remap to the palette available in the
				 destination image. This is slow and
				 works badly, but it beats crashing! Thanks
				 to Padhrig McCarthy. */
				mapTo = gdImageColorResolveAlpha (dst,
				                                  gdTrueColorGetRed (c),
				                                  gdTrueColorGetGreen (c),
				                                  gdTrueColorGetBlue (c),
				                                  gdTrueColorGetAlpha (c));
			} else if (colorMap[c] == (-1)) {
				/* If it's the same image, mapping is trivial */
				if (dst == src) {
					nc = c;
				} else {
					/* Get best match possible. This
					   function never returns error. */
					nc = gdImageColorResolveAlpha (dst,
					                               src->red[c], src->green[c],
					                               src->blue[c], src->alpha[c]);
				}
				colorMap[c] = nc;
				mapTo = colorMap[c];
			} else {
				mapTo = colorMap[c];
			}
			gdImageSetPixel (dst, tox, toy, mapTo);
			tox++;
		}
		toy++;
	}
}

/* This function is a substitute for real alpha channel operations,
   so it doesn't pay attention to the alpha channel. */
BGD_DECLARE(void) gdImageCopyMerge (gdImagePtr dst, gdImagePtr src, int dstX, int dstY,
									int srcX, int srcY, int w, int h, int pct)
{

	int c, dc;
	int x, y;
	int tox, toy;
	int ncR, ncG, ncB;
	toy = dstY;
	for (y = srcY; (y < (srcY + h)); y++) {
		tox = dstX;
		for (x = srcX; (x < (srcX + w)); x++) {
			int nc;
			c = gdImageGetPixel (src, x, y);
			/* Added 7/24/95: support transparent copies */
			if (gdImageGetTransparent (src) == c) {
				tox++;
				continue;
			}
			/* If it's the same image, mapping is trivial */
			if (dst == src) {
				nc = c;
			} else {
				dc = gdImageGetPixel (dst, tox, toy);

				ncR = gdImageRed (src, c) * (pct / 100.0)
				      + gdImageRed (dst, dc) * ((100 - pct) / 100.0);
				ncG = gdImageGreen (src, c) * (pct / 100.0)
				      + gdImageGreen (dst, dc) * ((100 - pct) / 100.0);
				ncB = gdImageBlue (src, c) * (pct / 100.0)
				      + gdImageBlue (dst, dc) * ((100 - pct) / 100.0);

				/* Find a reasonable color */
				nc = gdImageColorResolve (dst, ncR, ncG, ncB);
			}
			gdImageSetPixel (dst, tox, toy, nc);
			tox++;
		}
		toy++;
	}
}

/* This function is a substitute for real alpha channel operations,
   so it doesn't pay attention to the alpha channel. */
BGD_DECLARE(void) gdImageCopyMergeGray (gdImagePtr dst, gdImagePtr src, int dstX, int dstY,
										int srcX, int srcY, int w, int h, int pct)
{

	int c, dc;
	int x, y;
	int tox, toy;
	int ncR, ncG, ncB;
	float g;
	toy = dstY;
	for (y = srcY; (y < (srcY + h)); y++) {
		tox = dstX;
		for (x = srcX; (x < (srcX + w)); x++) {
			int nc;
			c = gdImageGetPixel (src, x, y);
			/* Added 7/24/95: support transparent copies */
			if (gdImageGetTransparent (src) == c) {
				tox++;
				continue;
			}
			/*
			 * If it's the same image, mapping is NOT trivial since we
			 * merge with greyscale target, but if pct is 100, the grey
			 * value is not used, so it becomes trivial. pjw 2.0.12.
			 */
			if (dst == src && pct == 100) {
				nc = c;
			} else {
				dc = gdImageGetPixel (dst, tox, toy);
				g = 0.29900 * gdImageRed(dst, dc)
				    + 0.58700 * gdImageGreen(dst, dc) + 0.11400 * gdImageBlue(dst, dc);

				ncR = gdImageRed (src, c) * (pct / 100.0)
				      + g * ((100 - pct) / 100.0);
				ncG = gdImageGreen (src, c) * (pct / 100.0)
				      + g * ((100 - pct) / 100.0);
				ncB = gdImageBlue (src, c) * (pct / 100.0)
				      + g * ((100 - pct) / 100.0);

				/* First look for an exact match */
				nc = gdImageColorExact (dst, ncR, ncG, ncB);
				if (nc == (-1)) {
					/* No, so try to allocate it */
					nc = gdImageColorAllocate (dst, ncR, ncG, ncB);
					/* If we're out of colors, go for the
					   closest color */
					if (nc == (-1)) {
						nc = gdImageColorClosest (dst, ncR, ncG, ncB);
					}
				}
			}
			gdImageSetPixel (dst, tox, toy, nc);
			tox++;
		}
		toy++;
	}
}

BGD_DECLARE(void) gdImageCopyResized (gdImagePtr dst, gdImagePtr src, int dstX, int dstY,
									  int srcX, int srcY, int dstW, int dstH, int srcW,
									  int srcH)
{
	int c;
	int x, y;
	int tox, toy;
	int ydest;
	int i;
	int colorMap[gdMaxColors];
	/* Stretch vectors */
	int *stx;
	int *sty;
	/* We only need to use floating point to determine the correct
	   stretch vector for one line's worth. */
	if (overflow2(sizeof (int), srcW)) {
		return;
	}
	if (overflow2(sizeof (int), srcH)) {
		return;
	}
	stx = (int *) gdMalloc (sizeof (int) * srcW);
	if (!stx) {
		return;
	}

	sty = (int *) gdMalloc (sizeof (int) * srcH);
	if (!sty) {
		gdFree(stx);
		return;
	}

	/* Fixed by Mao Morimoto 2.0.16 */
	for (i = 0; (i < srcW); i++) {
		stx[i] = dstW * (i + 1) / srcW - dstW * i / srcW;
	}
	for (i = 0; (i < srcH); i++) {
		sty[i] = dstH * (i + 1) / srcH - dstH * i / srcH;
	}
	for (i = 0; (i < gdMaxColors); i++) {
		colorMap[i] = (-1);
	}
	toy = dstY;
	for (y = srcY; (y < (srcY + srcH)); y++) {
		for (ydest = 0; (ydest < sty[y - srcY]); ydest++) {
			tox = dstX;
			for (x = srcX; (x < (srcX + srcW)); x++) {
				int nc = 0;
				int mapTo;
				if (!stx[x - srcX]) {
					continue;
				}
				if (dst->trueColor) {
					/* 2.0.9: Thorben Kundinger: Maybe the source image is not
					   a truecolor image */
					if (!src->trueColor) {
						int tmp = gdImageGetPixel (src, x, y);
						mapTo = gdImageGetTrueColorPixel (src, x, y);
						if (gdImageGetTransparent (src) == tmp) {
							/* 2.0.21, TK: not tox++ */
							tox += stx[x - srcX];
							continue;
						}
					} else {
						/* TK: old code follows */
						mapTo = gdImageGetTrueColorPixel (src, x, y);
						/* Added 7/24/95: support transparent copies */
						if (gdImageGetTransparent (src) == mapTo) {
							/* 2.0.21, TK: not tox++ */
							tox += stx[x - srcX];
							continue;
						}
					}
				} else {
					c = gdImageGetPixel (src, x, y);
					/* Added 7/24/95: support transparent copies */
					if (gdImageGetTransparent (src) == c) {
						tox += stx[x - srcX];
						continue;
					}
					if (src->trueColor) {
						/* Remap to the palette available in the
						   destination image. This is slow and
						   works badly. */
						mapTo = gdImageColorResolveAlpha (dst,
						                                  gdTrueColorGetRed (c),
						                                  gdTrueColorGetGreen
						                                  (c),
						                                  gdTrueColorGetBlue
						                                  (c),
						                                  gdTrueColorGetAlpha
						                                  (c));
					} else {
						/* Have we established a mapping for this color? */
						if (colorMap[c] == (-1)) {
							/* If it's the same image, mapping is trivial */
							if (dst == src) {
								nc = c;
							} else {
								/* Find or create the best match */
								/* 2.0.5: can't use gdTrueColorGetRed, etc with palette */
								nc = gdImageColorResolveAlpha (dst,
								                               gdImageRed (src,
								                                       c),
								                               gdImageGreen
								                               (src, c),
								                               gdImageBlue (src,
								                                       c),
								                               gdImageAlpha
								                               (src, c));
							}
							colorMap[c] = nc;
						}
						mapTo = colorMap[c];
					}
				}
				for (i = 0; (i < stx[x - srcX]); i++) {
					gdImageSetPixel (dst, tox, toy, mapTo);
					tox++;
				}
			}
			toy++;
		}
	}
	gdFree (stx);
	gdFree (sty);
}

/* gd 2.0.8: gdImageCopyRotated is added. Source
	is a rectangle, with its upper left corner at
	srcX and srcY. Destination is the *center* of
		the rotated copy. Angle is in degrees, same as
		gdImageArc. Floating point destination center
	coordinates allow accurate rotation of
	objects of odd-numbered width or height. */

BGD_DECLARE(void) gdImageCopyRotated (gdImagePtr dst,
									  gdImagePtr src,
									  double dstX, double dstY,
									  int srcX, int srcY,
									  int srcWidth, int srcHeight, int angle)
{
	double dx, dy;
	double radius = sqrt (srcWidth * srcWidth + srcHeight * srcHeight);
	double aCos = cos (angle * .0174532925);
	double aSin = sin (angle * .0174532925);
	double scX = srcX + ((double) srcWidth) / 2;
	double scY = srcY + ((double) srcHeight) / 2;
	int cmap[gdMaxColors];
	int i;

	/*
		 2.0.34: transparency preservation. The transparentness of
		 the transparent color is more important than its hue.
	*/
	if (src->transparent != -1) {
		if (dst->transparent == -1) {
			dst->transparent = src->transparent;
		}
	}

	for (i = 0; (i < gdMaxColors); i++) {
		cmap[i] = (-1);
	}
	for (dy = dstY - radius; (dy <= dstY + radius); dy++) {
		for (dx = dstX - radius; (dx <= dstX + radius); dx++) {
			double sxd = (dx - dstX) * aCos - (dy - dstY) * aSin;
			double syd = (dy - dstY) * aCos + (dx - dstX) * aSin;
			int sx = sxd + scX;
			int sy = syd + scY;
			if ((sx >= srcX) && (sx < srcX + srcWidth) &&
			        (sy >= srcY) && (sy < srcY + srcHeight)) {
				int c = gdImageGetPixel (src, sx, sy);
				/* 2.0.34: transparency wins */
				if (c == src->transparent) {
					gdImageSetPixel (dst, dx, dy, dst->transparent);
				} else if (!src->trueColor) {
					/* Use a table to avoid an expensive
					   lookup on every single pixel */
					if (cmap[c] == -1) {
						cmap[c] = gdImageColorResolveAlpha (dst,
						                                    gdImageRed (src, c),
						                                    gdImageGreen (src,
						                                            c),
						                                    gdImageBlue (src,
						                                            c),
						                                    gdImageAlpha (src,
						                                            c));
					}
					gdImageSetPixel (dst, dx, dy, cmap[c]);
				} else {
					gdImageSetPixel (dst,
					                 dx, dy,
					                 gdImageColorResolveAlpha (dst,
					                         gdImageRed (src,
					                                     c),
					                         gdImageGreen
					                         (src, c),
					                         gdImageBlue (src,
					                                      c),
					                         gdImageAlpha
					                         (src, c)));
				}
			}
		}
	}
}

/* When gd 1.x was first created, floating point was to be avoided.
   These days it is often faster than table lookups or integer
   arithmetic. The routine below is shamelessly, gloriously
   floating point. TBB */

/* 2.0.10: cast instead of floor() yields 35% performance improvement.
	Thanks to John Buckman. */

#define floor2(exp) ((long) exp)
/*#define floor2(exp) floor(exp)*/

BGD_DECLARE(void) gdImageCopyResampled (gdImagePtr dst,
										gdImagePtr src,
										int dstX, int dstY,
										int srcX, int srcY,
										int dstW, int dstH, int srcW, int srcH)
{
	int x, y;
	double sy1, sy2, sx1, sx2;
	if (!dst->trueColor) {
		gdImageCopyResized (dst, src, dstX, dstY, srcX, srcY, dstW, dstH,
		                    srcW, srcH);
		return;
	}
	for (y = dstY; (y < dstY + dstH); y++) {
		sy1 = ((double) y - (double) dstY) * (double) srcH / (double) dstH;
		sy2 = ((double) (y + 1) - (double) dstY) * (double) srcH /
		      (double) dstH;
		for (x = dstX; (x < dstX + dstW); x++) {
			double sx, sy;
			double spixels = 0;
			double red = 0.0, green = 0.0, blue = 0.0, alpha = 0.0;
			double alpha_sum = 0.0, contrib_sum = 0.0;

			sx1 = ((double) x - (double) dstX) * (double) srcW / dstW;
			sx2 = ((double) (x + 1) - (double) dstX) * (double) srcW / dstW;
			sy = sy1;
			do {
				double yportion;
				if (floor2 (sy) == floor2 (sy1)) {
					yportion = 1.0 - (sy - floor2 (sy));
					if (yportion > sy2 - sy1) {
						yportion = sy2 - sy1;
					}
					sy = floor2 (sy);
				} else if (sy == floor2 (sy2)) {
					yportion = sy2 - floor2 (sy2);
				} else {
					yportion = 1.0;
				}
				sx = sx1;
				do {
					double xportion;
					double pcontribution;
					int p;
					if (floor2 (sx) == floor2 (sx1)) {
						xportion = 1.0 - (sx - floor2 (sx));
						if (xportion > sx2 - sx1) {
							xportion = sx2 - sx1;
						}
						sx = floor2 (sx);
					} else if (sx == floor2 (sx2)) {
						xportion = sx2 - floor2 (sx2);
					} else {
						xportion = 1.0;
					}
					pcontribution = xportion * yportion;
					/* 2.08: previously srcX and srcY were ignored.
					   Andrew Pattison */
					p = gdImageGetTrueColorPixel (src,
					                              (int) sx + srcX,
					                              (int) sy + srcY);
					red += gdTrueColorGetRed (p) * pcontribution;
					green += gdTrueColorGetGreen (p) * pcontribution;
					blue += gdTrueColorGetBlue (p) * pcontribution;
					alpha += gdTrueColorGetAlpha (p) * pcontribution;
					spixels += xportion * yportion;
					sx += 1.0;
				} while (sx < sx2);
				sy += 1.0;
			} while (sy < sy2);
			if (spixels != 0.0) {
				red /= spixels;
				green /= spixels;
				blue /= spixels;
				alpha /= spixels;
				alpha += 0.5;
			}
			if ( alpha_sum != 0.0f) {
				if( contrib_sum != 0.0f) {
					alpha_sum /= contrib_sum;
				}
				red /= alpha_sum;
				green /= alpha_sum;
				blue /= alpha_sum;
			}
			/* Clamping to allow for rounding errors above */
			if (red > 255.0) {
				red = 255.0;
			}
			if (green > 255.0) {
				green = 255.0;
			}
			if (blue > 255.0) {
				blue = 255.0;
			}
			if (alpha > gdAlphaMax) {
				alpha = gdAlphaMax;
			}
			gdImageSetPixel (dst,
			                 x, y,
			                 gdTrueColorAlpha ((int) red,
			                                   (int) green,
			                                   (int) blue, (int) alpha));
		}
	}
}

BGD_DECLARE(void) gdImagePolygon (gdImagePtr im, gdPointPtr p, int n, int c)
{
	if (n <= 0) {
		return;
	}


	gdImageLine (im, p->x, p->y, p[n - 1].x, p[n - 1].y, c);
	gdImageOpenPolygon (im, p, n, c);
}

BGD_DECLARE(void) gdImageOpenPolygon (gdImagePtr im, gdPointPtr p, int n, int c)
{
	int i;
	int lx, ly;
	if (n <= 0) {
		return;
	}


	lx = p->x;
	ly = p->y;
	for (i = 1; (i < n); i++) {
		p++;
		gdImageLine (im, lx, ly, p->x, p->y, c);
		lx = p->x;
		ly = p->y;
	}

}

/* THANKS to Kirsten Schulz for the polygon fixes! */

/* The intersection finding technique of this code could be improved  */
/* by remembering the previous intertersection, and by using the slope. */
/* That could help to adjust intersections  to produce a nice */
/* interior_extrema. */

BGD_DECLARE(void) gdImageFilledPolygon (gdImagePtr im, gdPointPtr p, int n, int c)
{
	int i;
	int j;
	int index;
	int y;
	int miny, maxy, pmaxy;
	int x1, y1;
	int x2, y2;
	int ind1, ind2;
	int ints;
	int fill_color;
	if (n <= 0) {
		return;
	}

	if (c == gdAntiAliased) {
		fill_color = im->AA_color;
	} else {
		fill_color = c;
	}
	if (!im->polyAllocated) {
		if (overflow2(sizeof (int), n)) {
			return;
		}
		im->polyInts = (int *) gdMalloc (sizeof (int) * n);
		if (!im->polyInts) {
			return;
		}
		im->polyAllocated = n;
	}
	if (im->polyAllocated < n) {
		while (im->polyAllocated < n) {
			im->polyAllocated *= 2;
		}
		if (overflow2(sizeof (int), im->polyAllocated)) {
			return;
		}
		im->polyInts = (int *) gdReallocEx (im->polyInts,
						    sizeof (int) * im->polyAllocated);
		if (!im->polyInts) {
			return;
		}
	}
	miny = p[0].y;
	maxy = p[0].y;
	for (i = 1; (i < n); i++) {
		if (p[i].y < miny) {
			miny = p[i].y;
		}
		if (p[i].y > maxy) {
			maxy = p[i].y;
		}
	}
	pmaxy = maxy;
	/* 2.0.16: Optimization by Ilia Chipitsine -- don't waste time offscreen */
	/* 2.0.26: clipping rectangle is even better */
	if (miny < im->cy1) {
		miny = im->cy1;
	}
	if (maxy > im->cy2) {
		maxy = im->cy2;
	}
	/* Fix in 1.3: count a vertex only once */
	for (y = miny; (y <= maxy); y++) {
		ints = 0;
		for (i = 0; (i < n); i++) {
			if (!i) {
				ind1 = n - 1;
				ind2 = 0;
			} else {
				ind1 = i - 1;
				ind2 = i;
			}
			y1 = p[ind1].y;
			y2 = p[ind2].y;
			if (y1 < y2) {
				x1 = p[ind1].x;
				x2 = p[ind2].x;
			} else if (y1 > y2) {
				y2 = p[ind1].y;
				y1 = p[ind2].y;
				x2 = p[ind1].x;
				x1 = p[ind2].x;
			} else {
				continue;
			}

			/* Do the following math as float intermediately, and round to ensure
			 * that Polygon and FilledPolygon for the same set of points have the
			 * same footprint. */

			if ((y >= y1) && (y < y2)) {
				im->polyInts[ints++] = (int) ((float) ((y - y1) * (x2 - x1)) /
				                              (float) (y2 - y1) + 0.5 + x1);
			} else if ((y == pmaxy) && (y == y2)) {
				im->polyInts[ints++] = x2;
			}
		}
		/*
		  2.0.26: polygons pretty much always have less than 100 points,
		  and most of the time they have considerably less. For such trivial
		  cases, insertion sort is a good choice. Also a good choice for
		  future implementations that may wish to indirect through a table.
		*/
		for (i = 1; (i < ints); i++) {
			index = im->polyInts[i];
			j = i;
			while ((j > 0) && (im->polyInts[j - 1] > index)) {
				im->polyInts[j] = im->polyInts[j - 1];
				j--;
			}
			im->polyInts[j] = index;
		}
		for (i = 0; (i < (ints-1)); i += 2) {
			/* 2.0.29: back to gdImageLine to prevent segfaults when
			  performing a pattern fill */
			gdImageLine (im, im->polyInts[i], y, im->polyInts[i + 1], y,
			             fill_color);
		}
	}
	/* If we are drawing this AA, then redraw the border with AA lines. */
	/* This doesn't work as well as I'd like, but it doesn't clash either. */
	if (c == gdAntiAliased) {
		gdImagePolygon (im, p, n, c);
	}
}

static void gdImageSetAAPixelColor(gdImagePtr im, int x, int y, int color, int t);

BGD_DECLARE(void) gdImageSetStyle (gdImagePtr im, int *style, int noOfPixels)
{
	if (im->style) {
		gdFree (im->style);
	}
	if (overflow2(sizeof (int), noOfPixels)) {
		return;
	}
	im->style = (int *) gdMalloc (sizeof (int) * noOfPixels);
	if (!im->style) {
		return;
	}
	memcpy (im->style, style, sizeof (int) * noOfPixels);
	im->styleLength = noOfPixels;
	im->stylePos = 0;
}

BGD_DECLARE(void) gdImageSetThickness (gdImagePtr im, int thickness)
{
	im->thick = thickness;
}

BGD_DECLARE(void) gdImageSetBrush (gdImagePtr im, gdImagePtr brush)
{
	int i;
	im->brush = brush;
	if ((!im->trueColor) && (!im->brush->trueColor)) {
		for (i = 0; (i < gdImageColorsTotal (brush)); i++) {
			int index;
			index = gdImageColorResolveAlpha (im,
			                                  gdImageRed (brush, i),
			                                  gdImageGreen (brush, i),
			                                  gdImageBlue (brush, i),
			                                  gdImageAlpha (brush, i));
			im->brushColorMap[i] = index;
		}
	}
}

BGD_DECLARE(void) gdImageSetTile (gdImagePtr im, gdImagePtr tile)
{
	int i;
	im->tile = tile;
	if ((!im->trueColor) && (!im->tile->trueColor)) {
		for (i = 0; (i < gdImageColorsTotal (tile)); i++) {
			int index;
			index = gdImageColorResolveAlpha (im,
			                                  gdImageRed (tile, i),
			                                  gdImageGreen (tile, i),
			                                  gdImageBlue (tile, i),
			                                  gdImageAlpha (tile, i));
			im->tileColorMap[i] = index;
		}
	}
}

BGD_DECLARE(void) gdImageSetAntiAliased (gdImagePtr im, int c)
{
	im->AA = 1;
	im->AA_color = c;
	im->AA_dont_blend = -1;
}

BGD_DECLARE(void) gdImageSetAntiAliasedDontBlend (gdImagePtr im, int c, int dont_blend)
{
	im->AA = 1;
	im->AA_color = c;
	im->AA_dont_blend = dont_blend;
}

BGD_DECLARE(void) gdImageInterlace (gdImagePtr im, int interlaceArg)
{
	im->interlace = interlaceArg;
}

BGD_DECLARE(int) gdImageCompare (gdImagePtr im1, gdImagePtr im2)
{
	int x, y;
	int p1, p2;
	int cmpStatus = 0;
	int sx, sy;

	if (im1->interlace != im2->interlace) {
		cmpStatus |= GD_CMP_INTERLACE;
	}

	if (im1->transparent != im2->transparent) {
		cmpStatus |= GD_CMP_TRANSPARENT;
	}

	if (im1->trueColor != im2->trueColor) {
		cmpStatus |= GD_CMP_TRUECOLOR;
	}

	sx = im1->sx;
	if (im1->sx != im2->sx) {
		cmpStatus |= GD_CMP_SIZE_X + GD_CMP_IMAGE;
		if (im2->sx < im1->sx) {
			sx = im2->sx;
		}
	}

	sy = im1->sy;
	if (im1->sy != im2->sy) {
		cmpStatus |= GD_CMP_SIZE_Y + GD_CMP_IMAGE;
		if (im2->sy < im1->sy) {
			sy = im2->sy;
		}
	}

	if (im1->colorsTotal != im2->colorsTotal) {
		cmpStatus |= GD_CMP_NUM_COLORS;
	}

	for (y = 0; (y < sy); y++) {
		for (x = 0; (x < sx); x++) {
			p1 =
			    im1->trueColor ? gdImageTrueColorPixel (im1, x,
			            y) :
			    gdImagePalettePixel (im1, x, y);
			p2 =
			    im2->trueColor ? gdImageTrueColorPixel (im2, x,
			            y) :
			    gdImagePalettePixel (im2, x, y);
			if (gdImageRed (im1, p1) != gdImageRed (im2, p2)) {
				cmpStatus |= GD_CMP_COLOR + GD_CMP_IMAGE;
				break;
			}
			if (gdImageGreen (im1, p1) != gdImageGreen (im2, p2)) {
				cmpStatus |= GD_CMP_COLOR + GD_CMP_IMAGE;
				break;
			}
			if (gdImageBlue (im1, p1) != gdImageBlue (im2, p2)) {
				cmpStatus |= GD_CMP_COLOR + GD_CMP_IMAGE;
				break;
			}
#if 0
			/* Soon we'll add alpha channel to palettes */
			if (gdImageAlpha (im1, p1) != gdImageAlpha (im2, p2)) {
				cmpStatus |= GD_CMP_COLOR + GD_CMP_IMAGE;
				break;
			}
#endif
		}
		if (cmpStatus & GD_CMP_COLOR) {
			break;
		};
	}

	return cmpStatus;
}


/* Thanks to Frank Warmerdam for this superior implementation
	of gdAlphaBlend(), which merges alpha in the
	destination color much better. */

BGD_DECLARE(int) gdAlphaBlend (int dst, int src)
{
	int src_alpha = gdTrueColorGetAlpha(src);
	int dst_alpha, alpha, red, green, blue;
	int src_weight, dst_weight, tot_weight;

	/* -------------------------------------------------------------------- */
	/*      Simple cases we want to handle fast.                            */
	/* -------------------------------------------------------------------- */
	if( src_alpha == gdAlphaOpaque )
		return src;

	dst_alpha = gdTrueColorGetAlpha(dst);
	if( src_alpha == gdAlphaTransparent )
		return dst;
	if( dst_alpha == gdAlphaTransparent )
		return src;

	/* -------------------------------------------------------------------- */
	/*      What will the source and destination alphas be?  Note that      */
	/*      the destination weighting is substantially reduced as the       */
	/*      overlay becomes quite opaque.                                   */
	/* -------------------------------------------------------------------- */
	src_weight = gdAlphaTransparent - src_alpha;
	dst_weight = (gdAlphaTransparent - dst_alpha) * src_alpha / gdAlphaMax;
	tot_weight = src_weight + dst_weight;

	/* -------------------------------------------------------------------- */
	/*      What red, green and blue result values will we use?             */
	/* -------------------------------------------------------------------- */
	alpha = src_alpha * dst_alpha / gdAlphaMax;

	red = (gdTrueColorGetRed(src) * src_weight
	       + gdTrueColorGetRed(dst) * dst_weight) / tot_weight;
	green = (gdTrueColorGetGreen(src) * src_weight
	         + gdTrueColorGetGreen(dst) * dst_weight) / tot_weight;
	blue = (gdTrueColorGetBlue(src) * src_weight
	        + gdTrueColorGetBlue(dst) * dst_weight) / tot_weight;

	/* -------------------------------------------------------------------- */
	/*      Return merged result.                                           */
	/* -------------------------------------------------------------------- */
	return ((alpha << 24) + (red << 16) + (green << 8) + blue);
}

BGD_DECLARE(void) gdImageAlphaBlending (gdImagePtr im, int alphaBlendingArg)
{
	im->alphaBlendingFlag = alphaBlendingArg;
}

BGD_DECLARE(void) gdImageSaveAlpha (gdImagePtr im, int saveAlphaArg)
{
	im->saveAlphaFlag = saveAlphaArg;
}

BGD_DECLARE(void) gdImageSetClip (gdImagePtr im, int x1, int y1, int x2, int y2)
{
	if (x1 < 0) {
		x1 = 0;
	}
	if (x1 >= im->sx) {
		x1 = im->sx - 1;
	}
	if (x2 < 0) {
		x2 = 0;
	}
	if (x2 >= im->sx) {
		x2 = im->sx - 1;
	}
	if (y1 < 0) {
		y1 = 0;
	}
	if (y1 >= im->sy) {
		y1 = im->sy - 1;
	}
	if (y2 < 0) {
		y2 = 0;
	}
	if (y2 >= im->sy) {
		y2 = im->sy - 1;
	}
	im->cx1 = x1;
	im->cy1 = y1;
	im->cx2 = x2;
	im->cy2 = y2;
}

BGD_DECLARE(void) gdImageGetClip (gdImagePtr im, int *x1P, int *y1P, int *x2P, int *y2P)
{
	*x1P = im->cx1;
	*y1P = im->cy1;
	*x2P = im->cx2;
	*y2P = im->cy2;
}

BGD_DECLARE(void) gdImageSetResolution(gdImagePtr im, const unsigned int res_x, const unsigned int res_y)
{
	if (res_x > 0) im->res_x = res_x;
	if (res_y > 0) im->res_y = res_y;
}

/*
 * Added on 2003/12 by Pierre-Alain Joye (pajoye@pearfr.org)
 * */
#define BLEND_COLOR(a, nc, c, cc) \
nc = (cc) + (((((c) - (cc)) * (a)) + ((((c) - (cc)) * (a)) >> 8) + 0x80) >> 8);

static void gdImageSetAAPixelColor(gdImagePtr im, int x, int y, int color, int t)
{
	int dr,dg,db,p,r,g,b;

	/* 2.0.34: watch out for out of range calls */
	if (!gdImageBoundsSafeMacro(im, x, y)) {
		return;
	}
	p = gdImageGetPixel(im,x,y);
	/* TBB: we have to implement the dont_blend stuff to provide
	  the full feature set of the old implementation */
	if ((p == color)
	        || ((p == im->AA_dont_blend)
	            && (t != 0x00))) {
		return;
	}
	dr = gdTrueColorGetRed(color);
	dg = gdTrueColorGetGreen(color);
	db = gdTrueColorGetBlue(color);

	r = gdTrueColorGetRed(p);
	g = gdTrueColorGetGreen(p);
	b = gdTrueColorGetBlue(p);

	BLEND_COLOR(t, dr, r, dr);
	BLEND_COLOR(t, dg, g, dg);
	BLEND_COLOR(t, db, b, db);
	im->tpixels[y][x] = gdTrueColorAlpha(dr, dg, db, gdAlphaOpaque);
}

static void gdImageAALine (gdImagePtr im, int x1, int y1, int x2, int y2, int col)
{
	/* keep them as 32bits */
	long x, y, inc, frac;
	long dx, dy,tmp;
	int w, wid, wstart; 
	int thick = im->thick; 

	if (!im->trueColor) {
		/* TBB: don't crash when the image is of the wrong type */
		gdImageLine(im, x1, y1, x2, y2, col);
		return;
	}

	/* TBB: use the clipping rectangle */
	if (clip_1d (&x1, &y1, &x2, &y2, im->cx1, im->cx2) == 0)
		return;
	if (clip_1d (&y1, &x1, &y2, &x2, im->cy1, im->cy2) == 0)
		return;

	dx = x2 - x1;
	dy = y2 - y1;

	if (dx == 0 && dy == 0) {
		/* TBB: allow setting points */
		gdImageSetAAPixelColor(im, x1, y1, col, 0xFF);
		return;
	} else {
		double ag;
		ag = (abs(dy) < abs(dx)) ? cos(atan2(dy, dx)) : sin(atan2(dy, dx));
		if (ag != 0) {
			wid = abs(thick / ag);
		} else {
			wid = 1;
		}
		if (wid == 0) {
			wid = 1;
		}
	}

	/* Axis aligned lines */
	if (dx == 0) {
		gdImageVLine(im, x1, y1, y2, col);
		return;
	} else if (dy == 0) {
		gdImageHLine(im, y1, x1, x2, col);
		return;
	}

	if (abs(dx) > abs(dy)) {
		if (dx < 0) {
			tmp = x1;
			x1 = x2;
			x2 = tmp;
			tmp = y1;
			y1 = y2;
			y2 = tmp;
			dx = x2 - x1;
			dy = y2 - y1;
		}
		y = y1;
		inc = (dy * 65536) / dx;
		frac = 0;
		/* TBB: set the last pixel for consistency (<=) */
		for (x = x1 ; x <= x2 ; x++) {
			wstart = y - wid / 2;
			for (w = wstart; w < wstart + wid; w++) {
			    gdImageSetAAPixelColor(im, x , w , col , (frac >> 8) & 0xFF);
			    gdImageSetAAPixelColor(im, x , w + 1 , col, (~frac >> 8) & 0xFF);
			}
			frac += inc;
			if (frac >= 65536) {
				frac -= 65536;
				y++;
			} else if (frac < 0) {
				frac += 65536;
				y--;
			}
		}
	} else {
		if (dy < 0) {
			tmp = x1;
			x1 = x2;
			x2 = tmp;
			tmp = y1;
			y1 = y2;
			y2 = tmp;
			dx = x2 - x1;
			dy = y2 - y1;
		}
		x = x1;
		inc = (dx * 65536) / dy;
		frac = 0;
		/* TBB: set the last pixel for consistency (<=) */
		for (y = y1 ; y <= y2 ; y++) {
			wstart = x - wid / 2;
			for (w = wstart; w < wstart + wid; w++) {
			    gdImageSetAAPixelColor(im, w , y  , col, (frac >> 8) & 0xFF);
			    gdImageSetAAPixelColor(im, w + 1, y, col, (~frac >> 8) & 0xFF);
			}
			frac += inc;
			if (frac >= 65536) {
				frac -= 65536;
				x++;
			} else if (frac < 0) {
				frac += 65536;
				x--;
			}
		}
	}
}


/* convert a palette image to true color */
BGD_DECLARE(int) gdImagePaletteToTrueColor(gdImagePtr src)
{
	unsigned int y;
	unsigned int yy;

	if (src == NULL) {
		return 0;
	}

	if (src->trueColor == 1) {
		return 1;
	} else {
		unsigned int x;
		const unsigned int sy = gdImageSY(src);
		const unsigned int sx = gdImageSX(src);

		src->tpixels = (int **) gdMalloc(sizeof(int *) * sy);
		if (src->tpixels == NULL) {
			return 0;
		}

		for (y = 0; y < sy; y++) {
			const unsigned char *src_row = src->pixels[y];
			int * dst_row;

			/* no need to calloc it, we overwrite all pxl anyway */
			src->tpixels[y] = (int *) gdMalloc(sx * sizeof(int));
			if (src->tpixels[y] == NULL) {
				goto clean_on_error;
			}

			dst_row = src->tpixels[y];
			for (x = 0; x < sx; x++) {
				const unsigned char c = *(src_row + x);
				if (c == src->transparent) {
					*(dst_row + x) = gdTrueColorAlpha(0, 0, 0, 127);;
				} else {
					*(dst_row + x) = gdTrueColorAlpha(src->red[c], src->green[c], src->blue[c], src->alpha[c]);
				}
			}
		}
	}

	/* free old palette buffer */
	for (yy = y - 1; yy >= yy - 1; yy--) {
		gdFree(src->pixels[yy]);
	}
	gdFree(src->pixels);
	src->trueColor = 1;
	src->pixels = NULL;
	src->alphaBlendingFlag = 0;
	src->saveAlphaFlag = 1;
	return 1;

clean_on_error:
	if (y > 0) {

		for (yy = y; yy >= yy - 1; y--) {
			gdFree(src->tpixels[y]);
		}
		gdFree(src->tpixels);
	}
	return 0;
}
